Thursday 4 June 2009

Dr. Joydev Profile

1. Name: DR. JOYDEV DINDA

2. Father’s Name: Mr. Anil Kumar Dinda
3. Permanent Address: Dr. Joydev Dinda, Vill. - Begunabari, P.O. - Lakshi,
Dist.-Purba Medinipur, Pin code -721430, W.B., India.
4. Commun. Address: Dr. J. Dinda, C/O- Santi Ranjan Saha, 20/2–Sitala Mandir Road, Garfa, Jadavpur, Kol-700075, WB, India.
5. E-mail Address: dindajoy@yahoo.com (mobile: 00-91-9733058113)
6. Date of Birth: 6 th July, 1974
7. Marital Status: Married
8. Sex: Male
9. Nationality: Indian

10. Educational Qualification:
Graduation ( B. Sc. (Hons.) in Chemisry): Bajkul Milani Mahavidyalaya, under Vidyasagar University in 1996 (2nd Class - 59.25%).
Post Graduation (M. Sc. in Chemistry): Vidyasagar University in 1998 (1St Class - 71.6%),
Ph.D.: Thesis entitled “Studies on Metallo-Organic Compounds of Naphthylazo and Azomethine Heterocycle”, awarded on 22.07.03 in the Department of Chemistry, University of Burdwan.
11. National Awards / Recognitions:
GATE: (Graduate Aptitude Test in Engineering): in 1999 with 81.13 percentile.
NET: (National Eligibility Test): in December 1999.
12. National Scholarship Received: scholarship from WB Govt. in Secondary Exam.
13. Internatinal Fellowships Received:
(a) National Science Council, NSC, Taiwan- Post Doctoral Research Fellowship, 2004- National Dong Hwa University, Hualien, Taiwan.
(b) Deutsche Forschungsgemeinschaft, DFG, Germany -Post Doctoral Research Fellowship, 2005 - Heidelberg University, Heidelberg, Germany.
(c) Minstry of Education and Culture, Spain – Post Doctoral research Fellowship,2006 -“Region of Murcia Science and Tech. plan-2003-2006”- Murcia University, Murcia, Spain.
(d) Central National Research Scientific,CNRS, France - Post Doctoral research Fellowship,2007- Universite Joseph Fourier, Grenoble, France.
14. National Fellowships received:
(a) Department of Science and Technology, DST- Project Assistance (July-August,1999),IIT, Kanpur, India
(b) Department of Science and Technology, DST- Junior Research Fellow (Feb.2000-January, 2002), Burdwan University, Burdwan, WB, India.
(c) Council for Scientific and Industrial Research, CSIR- Research associate (Nov.2003-Sept.2004), Burdwan University, Burdwan, WB, India.
(d) Council for Scientific and Industrial Research, CSIR- Research associate (June 2006 January 2007), Jadavpur University, Kolkata, WB, India.
15. Position occupied:
Research Assistance: Department of Chemistry, Indian Institute of Technology (IIT), Kanpur, India (July-August,1999), DST sanction project of Prof. R. N. Mukherjee.
Research Associate: (a)Department of Chemistry, Burdwan University, Burdwan (Nov., 2003 – Sept.,2004) & (b) Department of Chemistry, Jadavpur University, Kolkata (June,2006 –January, 2007) under the supervision of Dr. C. R. sinha.
16. Post Doctoral Research Experience:
(a) Department of Chemistry, National Dong Hwa University, Taiwan, Expert collaborator
of Prof. Wen –Shu Hwang, Prof.& President of Chemistry, National Dong - Hwa University
(period; September, 2004 –July, 2005) .
(b) Department of Chemistry, Inorganic Institute, Heidelberg University, Germany, Expert
collaborator of Prof. Walter Siebert, Heidelberg University (period;Sept.,2005-Feb., 2006).
(c) Department of Molecular Chemistry, University of Joseph Fourier, Grenoble France -
Expert collaborator of Prof. Frederique Loiseau (May, 2008 – May,2009).
17. Present Position: Lecturer in Chemistry (Since 2007), School of Applied Science, Haldia Institute of Technology, Haldia, West Bengal, India (on leave from May, 2008- May 2009).
Established the “Applied Chemical Synthetic Research Laboratory” in 2007 and supervising 5 Ph.D. research scholars in the same department in the field of NH carbene chemistry and catalysis.
18. Research area: Broad area:- Synthetic organometallic Chemistry and catalysis: Synthesis, spectral characterization, electrochemical, photophysical properties of N-Heterocyclic Carbene Complexes and their application in catalysis and as anticancer drugs.
19. Achievements:
Nine years research in the field of synthesis, spectral characterization, electrochemical and photophysical properties of coordination and organometallic compounds of transition metals complexes. Research comprised in the field of Azoimine (-N = N –C = N -) function as well as a,a-diimine (- N = C –C = N -) functions. Current interest; design and Synthesis of organometallic complexes of N -Heterocyclic Carbene ligands and their application in catalysis and as anticancer drugs.
20. Instrumental Skill: UV-VIS-NIR, FT-IR, NMR Spectro photometer, Cyclic Voltammetry, GC- Mass , etc.
21. Other Experiences: proficiency in Computer, Operating Systems MS-DOS, MS-Word, Microcal Origin, Ortex 6S, CACAO, PLATON, ISI, Mercury 2,1, Ultra Chem. draw etc.
22. Participation in the National / International Seminar(s) / Symposium (s) (Abstracts accepted); 9
(a) Symposium on Modern Trend in Inorganic Chemistry MTIC-IX-2001,Dec.,12th, Kol.,India.
(b) Forth national Symposium in Chemistry (2002), NCL and university of Puna, Puna,India.
(c) 39th Annual convocation of Chemist 2002, Indian chemical society, Nagarjun University, Andrapradesh, India.
(d) Celebration of Chemistry, Chemical Research Society of India(Kolkata Chapter), First Scientific Meeting,01, August, 2003,IACS, Kolkata, India.
(e) Celebration of Chemistry, Chemical Research Society of India (Kol. Chapter),2nd Scientific Meeting,03, August, 2004, Chemistry Department, Burdwan University, Burdwan, WB
(f) 12th Bangla Vigyan Congress, 2003, Jadavpur University, Kolkata-32, WB, India
(g) Paci Chem, 2004, Hawai, USA.
(h) 14th Bangla Vigyan Congress, 2007, Jadavpur University, Kolkata32, WB, India
(i) “Nano Science and Technology”-2007, Haldia Institute of Technology, Haldia, WB.
23. Invited Talk- Contamination and Food poisoning” on 31st December, 2006, National service Scheme (NSS) of Bajkul Milani Mahavidlaya.
24. Other activities: Active participation in weekly research seminar, group discussion and involved in social work through National Service scheme(NSS). Convener of monthly research seminar in the dept.; School of Applied Science
25. Life Member: 1) Indian Association for Cultivation of Science (IACS), Kolkata.
2) Indian Chemical Society (Applied).


26. Faculty References:
(1) Prof. C. Sinha, Professor, Department of Inorganic Chemistry, Jadavpur University, Kolkata-700 032, West Bengal, India, E. mail: c_r_sinha@yahoo.com.
(2) Dr. Ambikesh Mahapatra, Reader, Department of Physical Chemistry, Jadavpur University, Kolkata-700 032, West Bengal, India, E. mail: ambikesh _ ju@yahoo.com.
(3) Prof. Frederique Loiseau, Department de Chimie Moleculaire, UMR CNRS 5250, Universite Joseph Fourier, Grenoble, France, E mail:frederique.loiseau@ujf-grenoble.fr.

27. National and International Collaboration:
(a) Spectroscopic Studies and X-ray Crystal Data: Prof. Frederique Loiseau and Damian Jouvenot, Department Chimie Redox, Universite Joseph Fourier, Grenoble, Cedex-9, France.
(b) X-ray Crystal Structure Analysis: Dr. Satyanarayan Pal, Department of Chemistry, NISER, Bhubaneswar, Orrisa.
(c) X-ray Crystal Data Collection and Structures Analysis: Prof. Anders Danopoulos,
School of Chemistry, Southampton University, Southampton, UK.


PUBLICATIONS IN NATIONAL AND INTARNATIONAL JOURNALS ONLY

Articles communicated and will be communicated very soon; as supervisor / principal investigator

1. “Pd(II)- NH Carbene Complexes of 2,6-bis(N-methylimidazolium) Pyrazine Chloride and Catalysis”

Joydev Dinda, Gourisannkar Roymahapatra, Tapastaru Samanta, Sirshendu Dasadhikari and Anders A. Denopoulos
Organic Letter, 2009, 00, 0000.
2. “Synthesis, Structure, Electrochemical and Photo-luminescent Behaviours of Cu(I), Ag(I) and Au(I) complexes 1,3-bis(2-pyridylmethyl)-1H Benzimidazolium Hexaflurophosphate”

Joydev Dinda, Sirshendu Dasadhikari, Tapastaru Samanta, Gourisannkar Roymahapatra, Damian Jouvenot and Frederique Loiseau
European Journal of Inorganic Chemistry, 2009, 00, 0000.
3. “Cu(I)-NH Carbene Complex of CNC Pincer 2,6-bis(N-methylimidazolium)Pyrazine Hexaflurophosphate and Its Catalysis”
Joydev Dinda, Gourisannkar Roymahapatra, Tapastaru Samanta, C. -H. Lee, Wen-Shu Hwang, Biswajit Das
Advaced Syn. and Catal., 2009, 00, 0000.
4. “Synthesis, Structure, Electrochemical Behaviours of Ru(II) and Pt(II)-carbene complexes of NCN-Pincer 1,3-bis(2-pyridylmethyl)-1H Benzimidazolium Chloride”

Joydev Dinda, Sirshendu Dasadhikari , Tapastaru Samanta , Gourisankar Roymahapatra , Frederique Loiseau and Damien Jouvenot
European Journal of Inorganic Chemistry, 2009, 00, 0000
5. “Synthesis, Structure and Electrochemical Properties of Ru(II) –NH Pincer Carbene Complexes of 2,6-bis(N-methyl-imidazolium / benzimidazolim)pyrazinechloride”

Gourisannkar Roymahapatra, Tapastaru Samanta , Sirshendu Dasadhikari, Wen –Shu Hwang, C.H. Lee, Joydev Dinda
Inorganic Chemistry, 2009, 00, 0000.
6. “Abnormal Pd(II)-carbene complex of pyridyl[1,2-a]{2-pyridylimidazole}-3-ylidine hexaflurophosphate, Synthesis, structure and catalysis”
Tapastaru Samanta, Gourisannkar Roymahapatra , Sirshendu Dasadhikari, Damien Jouvenot and Joydev Dinda
Chem. Commun., 2009, 00, 0000.
7. “Synthesis, Structure, Electrochemical Behaviours of Ru(II)- complexes of CNC-Pincer 2,6-bis(N1-methyl- N3-methyleneimidazolium / benzimidayolium)pyridine dibromide”

Joydev Dinda, Frederique Loiseau and Damien Jouvenot
European Journal of Inorganic Chemistry, 2009, 00, 0000
8. “Synthesis, Structure, Electrochemical Behaviours of Ru(II) and Pt(II)-carbene complexes of NCN-Pincer 1,3-bis(2-pyridylmethyl)-1H imidazolium Chloride”

Joydev Dinda, Frederique Loiseau and Damien Jouvenot

European Journal of Inorganic Chemistry, 2009, 00, 0000

9. “Silver(I) complex of tris-(imidazolemethylene)amine, synthesis, spectral characterisation and X-ray crystal structure”
Sirshendu Das Adhikari, C.-H. Lee, Wen –Shu Hwang and Joydev Dinda.*
Inorganic. Chem. Commun., 2009, 00.0000.

Published Articles:
2008
10. “Structure, spectra and electrochemistry of ruthenium-carbonyl complexes of
naphthylazoimidazole”
Tapan Kumar Mondal, Joydev Dinda, Jack Cheng, Tian-Huey Lu and Chittaranjan Sinha
Inorganica Chimica Acta, 2008, 361,2431-2438.
2007
11. “Osmium-carbonyl complexes of naphthylazoimidazoles. Single crystal X-ray structure of
Os(H)(CO)(PPh3)2(α-NaiEt)](PF6) {α-NaiEt = 1-ethyl-2-(naphthyl-α-azo)imidazole}”
T.K. Mondal, Joydev Dinda, Alexandra M.Z. Slawin, J. Derek Woollins and C. Sinha
Polyhedron, 2007,26, 600-606.
12. “Silver complex of 2-methyl-pyrimidine. Two dimensional coordination polymer”
Mrinal Kanti Paira, Joydev Dinda, Jian-Sung Wu, Tian-Huey Lu, Chittaranjan Sinha
J. Indian Chem. Soc., 2007, 84, 425.
13. “Synthesis, spectral characterization and photoluminescence properties of cadmium(II) complexes of N-[(2-pyridyl)methyliden]-α (or β)-aminonaphthalene (α- or β-NaiPy) and comparison with the complexes of 1-alkyl-2-(naphthyl-α (or β)-azo)imidazole. Single crystal X-ray structure of [Cd(β-NaiPy)2(ONO2)2] “
D. Das, B.G. Chand, Joydev Dinda and C. Sinha
Polyhedron, 2007, 25, 555.
14. “Zn(II), Cd(II) and Hg(II) complexes of 8-aminoquinoline. Synthesis, structure and photoluminescence property”
M.K. Paira, Joydev Dinda, T.H. Lu, A.R. Paital and C. Sinha
Polyhedron, 2007, 26, 3141.
2006
15. “Synthesis, spectral characterization, and electrochemistry of bis –(2,2’ – bipyridine) (1 –alkyl – 2- (naphthyl-a-azo)imidazole) ruthenium (II) complexes: X-ray crystal structure of [ bis –(2,2’ – bipyridine) {1 –ethyl – 2- (naphthyl-a-azo)imidazole)}] ruthenium (II) perchlorate”
Joydev Dinda, S. Senapoti, T. Mondal, A. D. Jana, M. Y. Chiang, T. –H. Lu and C. Sinha
Polyhedron, 2006, 25, 1125.
16. “Ru(0) –azoimine-carbonyl and Ru(II) –pyridyl-azo-imidazolecomplexes”
T. Mathur, Joydev Dinda, P. Datta, G. Mostafa and C.Sinha
.Polyhedron, 2006, 25, 2503.
17. “Polymuclear and tetranuclear Cuprous Iodide complexex from N-(2- thineylmethylidine)
2- pyridylamine derivatives”
Chen- Shiang Lee, Chih –Yu Wu, Wen – Shu Hwang and Joydev Dinda
Polyhedron, 2006, 25, 1798-1801.
18. “Reactions of diiron nonacarbonyl with pyrrolyl-, pyridyl- and thienyl-substituted azines: N-N bond cleavage, cyclometallation and C=N σ and π-bonding”
Chih-Yu Wu, Yi Chen, Shiau-Yi Jing, C.-S. Lee, Joydev Dinda and Wen-Shu Hwang
Polyhedron, 2006, 25, 3053.
19. “Synthesis, Structure and photoluminescence properties of Bis – (nitro)- bis {naphthyl-2-(2-pyridylehylene)amine} Zn(II)”
D. Das, Joydev Dinda, T. Mondal and C. Sinha
J. Indian Chem. Soc., 2006, 83, 861.
20. “Zn (II)- azid complexes of diimine and azoimine function. Synthesis, spectra and X-ray structures”
D. Das, B. G. Chand, K. K. Sarkar, Joydev Dinda and C. Sinha
Polyhedron, 2006,25, 2333.
21. “Structure and spectra of Silver (I) complexes of (naphthyl-(2-pyridylehylene)amine”
D. Das, Joydev Dinda, T. K. Mondal and C. Sinha
J. Indian Chem. Soc., 2006, 83, 342.
2004
22. “Silver(I) complexes of azoimine functions: Single crystal X-ray structure of bis-[1-ethyl-2-(naphthyl-a-azo)imidazole] silver(I) perchlorate”
Joydev Dinda, Sk. Jasimuddin, G. Mostafa, C. H. Hung andC. Sinha
Polyhedron., 2004, 23, 493
2003
23. “Copper(I)-Azoimidazoles: A Comparative Account on The Structure and Electronic Properties of Copper(I) Complexes of 1-Alkyl-2-(arylazo)imidazole and 1-Alkyl-2-(naphthyl-(a/b)-azo) imidazoles”
Joydev Dinda, U. S. Ray, G. Mostafa, T. –H. Lu, A. Usman, I. A. Razak,S.Chantrapromma, H.-K. Fun and C. Sinha
Polyhedron, 2003, 22, 247.
24. “Synthesis, spectral characterisation and redox studies of [1-alkyl-2-(napthyl-b-azo)imidazole] palladium(II) catecholates.”
G. K. Rauth, Joydev Dinda, Sk. Jasimuddin and C. Sinha
Trans. Met. Chem., 2003, 27, 88-95.
25. “Mercury(II) co-ordination complexes versus organomercuration of naphthylazoimidazoles. Single crystal X-ray structure of 1-etyl-2-(naphthyl--a-azo)imidazolium hexafluoro-phosphate”
Joydev Dinda, K. Bag, C. Sinha, G. Mostafa and T. –H. Lu
Polyhedron, 2003, 22,1367.

Thursday 14 May 2009

Water analysis

TURBIDITY
OUTLINE OF THE METHOD
The sample is matched against standard suspensions of fuller’s earth in water.
TERMINOLOGY
For the purpose of this test, the following definition shall apply. Scale Unit - Turbidity imparted by 1 mg of fullers earth when suspended in 1000 ml of distilled water.
PREPARATION OF TURBIDITY STANDARDS
Mix slowly with constant stirring 5.000 g of fullers earth previously dried and shifted through 75 micron IS Sieve with distilled water and dilute it to 1000 ml. Agitate intermittently for one hour and then allow to stand for 24 hours. Withdraw the supernatant liquid without disturbing the sediment. Vaporate about 50 ml of the removed liquid, dry the residue at 105 + 2 Deg. C and weigh the residue to determine the amount of clay in suspension. Prepare turbidity standards with this standardised stock suspension with distilled water. A drop of saturated mercuric chloride solution may be added as preservative. The standards are stable for three months.
PROCEDURE
Pour the sample after thorough shaking into a clear glass bottle of suitable capacity, say, one litre. Compare it with the turbidity standards contained in similar bottles, holding them against a suitable background and using a source of light which illuminates them equally and is placed so that no rays reach the eye directly. The sample and the standards shall be shaken simultaneously immediately before comparison. If the sample has turbidity over 100 units, dilute it with distilled water before testing and multiply the result with an appropriate factor.
NOTE: Comparison of turbidity may also be done with the help of suitable instruments.
COLOUR
OUTLINE OF THE METHOD
The colour of the sample is matched against a series of standards containing potassium chloroplatinate and cobalt chloride.

TERMINOLOGY
For the purpose of this test, the following definitions shall apply :
True Colour
Colour due to substances in solution, after removal of suspended matter.
Apparent Colour
Colour due to substances which are in solution as well as in suspension.
Hazen Unit
Colour obtained in a mixture containing either on milligram of Patinum or 2.49 mg of potassium chloroplatinate along with 2 mg of cobalt chloride (CoCl2.6H2O) in 1 litre of the solution.

APPARATUS
Nessler Tubes - Flat-bottom tube of thin colourless glass. Two types of tubes are required. The longer tubes shall be 45 cm tall and 2.5 cm in internal diameter. The shorter tubes shall be 30 cm tall and 1.7 cm in internal diameter. Tubes of any one type shall be identical in shape, and the depth measured internally from the graduation mark to the bottom shall not vary by more than 2 mm in the tubes used.
REAGENTS
Platinum or Potassium Chloroplatinate Aqua Regia - prepared by mixing one part by volume of concentrated nitric acid (conforming to IS:264-1950) with three parts by volume of concentrated hydrochloric acid (conforming to IS:265-1962). Cobalt Chloride-Crystalline, with the molecular composition CoCl2.6H2).
PROCEDURE
PREPARATION OF COLOUR STANDARDS
Dissolve 0.500 g of metallic platinum in aqua regia and remove nitric acid by repeated evaporation to dryness on water bath after addition of excess of concentrated hydrochloric acid (conforming to IS:265-1962). Dissolve the residue with 1.0 g of cobalt chloride in 100 ml of concentrated hydrochloric acid to obtain a bright solution, if necessary by warming. Dilute the solution to 1000 ml with distilled water. This stock solution has a colour of 500 Hazen units. A more convenient way of preparing the same solution is by dissolving 1.245 g of potassium chloroplatinate and 1.0 g of cobalt chloride in distilled water and diluting to 1 litre. Prepare a set of colour standards having colour 5, 10, 15, 20, 25, 30, 35, 40, 50, 60 and 70 Hazen units by diluting the stock solution with water. Protect these colour standards from evaporation and contamination when not in use. The colour standards shall be freshly prepared for each determination. But in routine practice, they may be used repeatedly, provided they are protected against evaporation and contamination when not in use.
PROCEDURE FOR CLEAR SAMPLES
For samples having turbidity under 5 mg/l, match the colour of the sample against the standard colours in the longer Nessler Tubes. Fill the tubes to mark and compare the colour by looking vertically downwards against a pure white surface. If the colour is found to exceed 70 units, dilute the sample with distilled water before comparison and multiply the result by appropriate factor. As matching is very difficult when the colour of the sample is below 5 Hazen units, report the colour as less than 5 Hazen units in such cases. When the colour of the sample exceeds 30 Hazen units, the comparison may, if desired, be made in the shorter Nessler tubes.
PROCEDURE FOR TURBID SAMPLES
If the sample has turbidity over 5 mg/l it becomes impossible to measure the true colour accurately by the method prescribed in PROCEDURE for clear samples and if an attempt is made, the value found shall be reported as "apparent colour". In the presence of turbidity, the true colour shall be determined after centrifuging. The sample shall be centrifuged until the supernate liquid is clear. The centrifuged clear sample shall be compared by the method prescribed in PROCEDURE for clear samples.
NOTE: For estimating true colour, filter paper shall not be used since that leads to erroneous results.
REPORT
The results of colour determination shall be excess in whole numbers and shall be recorded as follows :
Hazen Units
Less than 5 Report as "Less than 5 Hazen Units"
5 to 50 Report to the nearest 1 Hazen Unit
51 to 100 Report to the nearest 5 Hazen Unit
101 to 250 Report to the nearest 10 Hazen Unit
251 to 500 Report to the nearest 20 Hazen Unit

NOTE: The colour determination shall be made as early as possible after the collection of samples as certain biological change occurring in storage may affect the colour.

ELECTRICAL CONDUCTANCE
GENERAL
The unit of conductance is the mho or reciprocal ohm. Specific conductivity is the conductance at a specified temperature across a column of a liquid 1 cm2 in area and 1 cm long, and is expressed mhos per centimetre. This is an inconveniently large unit for water testing and it is usual to use the micromhos per centimetre known as the "dionic unit", which is one-millionth part of a mho per centimetre.
APPARATUS
Several kinds of apparatus are available. They generally consist of two parts.
CONDUCTIVITY CELL
Containing a pair of electrodes. The sample to be tested is poured into this cell. There are many forms of cell. One of the most convenient types is provided with a funnel for filling, a drain for emptying, and an overflow for maintaining constant level. Electrodes for use with samples having very low dissolved solids (such as condensates) should not be coated with platinum black. Platinum black which has been heated to redness until it is grey is suitable. Bright platinum or gold or heavily gold plated electrodes may be used. Some instruments are designed to work with particular form of conductivity cell, and are then calibrated directly in conductivity units. Other instruments, primarily introduced for more general application, are calibrated on conductance units and their readings require multiplication by a factor known as the "cell-constant" which shall be determined by experiment. Measuring Instrument - For measuring the electrical conductance (or the resistance which is the inverse of conductance) between the electrodes of the cell. There are several satisfactory commercial models. Operators, less they have adequate facilities, would be well advised to purchase a ready made instrument.
PROCEDURE
Determine the cell constant if necessary, either directly with a standard potassium chloride solution (say 0.002 N) or by comparison with a cell the constant of which is known accurately. (In the latter case, the concentration and nature of the electrolytes in the liquid which is used for the comparison should be the same and should be similar respectively to those of the liquids with which the cell is likely to be used in practice). Use some of the samples to wash out the conductivity cell thoroughly. Fill the conductivity cell with the sample. Measure the conductivity in accordance with the instructions of the instrument manufacturer.
Calculations
FOR INSTRUMENT READING RESISTANCE :
Electrical conductance, in dionic units
(or micromhos per centimetre) = 1 x 106
rk
Where r = Resistance in ohms, and k = Cell constant
FOR INSTRUMENT READING CONDUCTANCE :
Electrical conductance, in dionic units
(or micromhos per centimetre) = ck
Where c = conductance in micromhos, and k = cell constant
CORRELATION OF ELECTRICAL CONDUCTANCE TO TOTAL DISSOLVED SOLIDS
For water containing a given mixture of mineral salts, the electrical conductance is closely proportional to the dissolved solids. When the samples are known to be free from wide fluctuation in mineral content, the electrical conductance offers a quick means of computing the total dissolved solids. However, this PROCEDURE may be used only after ascertaining the appropriate conversion factor for a particular series of samples.
Electrical conductance
Dissolved Solids
TOTAL DISSOLVED SOLIDS
A well mixed filtered sample is evaporated in a weighed dish and dried to constant weight in an oven at 103 to 105 Deg. C. The increase in weight over that of the empty dish represents the total residue.
APPARATUS
1. Silica or porcelain dish of 100 ml capacity
2. Desicator
3. Oven
PROCEDURE
Ignite the clean evaporating dish at 550 + 50 Deg. C for 1 hour. Cool, desiccate and weigh. Transfer the measured sample to the preweighed dish and evaporate to dryness on a steam bath. Choose a sample volume that will yield a minimum residue of 25 mg to 250 mg. If necessary, add successive portions of sample to the same dish. Dry the evaporated sample for atleast 1 hour at 103 to 105 Deg. C. Cool the dish in a desiccator and weigh. Repeat the cycle of drying, cooling and weighing until a constant weight is obtained.
Calculations
Total dissolved solids, mg/litr = wt of residue x 1000
ml. of sample taken
SUSPENDED MATTERS
Suspended matter is the material retained on filter after filtration of a well mixed sample of water. The residue is dried at 103 to 105 Deg. C.
APPARATUS
1. Gooch crucible
2. Silica or porcelain evaporating dish of 100 ml capacity
3. Desiccator
4. Oven adjustable to constant temp of 103 - 105 Deg. C.
5. Water batch

PROCEDURE
Prepare a gooch crucible with asbestos (20 to 30 ml of 0.5% suspension of gooch asbestos added and washed under suction), dry and ignite at 500 Deg. C for atleast 30 minutes, cool and weigh. Filter a suitable volume of the well mixed sample through the crucible. Wash with distilled water, dry at 105 Deg. C for one hour. Weigh.
Calculations
Suspended matter, mg/lit = w x 106
V
Where,
w = wt. in g of the suspended matter
V = vol. in ml. of the sample taken for filteration
NOTE: If Gooch Crucible is not available, standard "Whatman" filter paper may be used.
EQUIVALENT MINERAL ACIDITY
All the chlorides, sulfates, nitrates of Ca, Mg, Na. etc. are converted to corresponding mineral acids when they come into contact with strongly acidic cation exchanger like Tulsion-42. When the Performance of the cation unit is satisfactory the EMA and free mineral acidity (FMA) will be one and the same. Therefore, to have thorough control over the cation unit, EMA test is necessary.
PRINCIPLE
Some quantity of the water is allowed to pass through a cation exchanger Tulsion - 42 in hydrogen form, the effluent is collected and titrated against standard alkali and EMA is expressed as CaCO3.

Ca } Cl Ca } Cl
R.H. + Mg } SO4 ----- R. Mg + H } SO4
Na } HCO3 Na } HCO3
REAGENTS
1. Strongly acidic cation exchanger Tulsion - 42 in H+ form.
2. 2 NHCl
3. Standard 0.02 N sodium hydroxide solution

PROCEDURE
A. REGENERATION OF RESIN COLUMN
1. Fill up the column with about 50 ml. of cation resin uniformly and soak it in DM water. Remove any air bubbles.
2. Regenerate with 200 ml of 2 N HCl at the rate of 5 ml/min.
3. Rinse it thoroughly with distilled water till the effluent becomes neutral.
4. Always keep some amount of distilled water over the column.
B. DETERMINATION
1. Add the water to be tested slowly and pass through the column at the rate of 5 ml/min.
2. Discard the first 50 ml portion of the effluent and collect the rest in flask.
3. Pipette out 50 ml from it and add 2 drops of mixed indicator. Titrate against standard 0.02 N NaOH.
Calculations
EMA, as CaCO3, mg/lit = ml. of titrant x 1000
ml of sample
ACIDITY
The acidity of a water may be caused by the presence of uncombined (free) carbon dioxide mineral acids and salts of strong acids and weak bases. The test is based on the titration of a sample with a standard solution of a strong base. Titration to the methyl orange end point (pH 4.5) is arbitrarily defined as "free acidity". It measures the relatively strong acids such as mineral acids. Titration to phenolphthalein end point pH 8.3 is defined as "total acidity" and it includes also the weak acids, acid salts, and some acidity due to hydrolysis.
REAGENTS
1. 0.02 N Sodium hydroxide.
2. Phenolphthalein indicator solution
3. Methyl orange indicator solution.

PROCEDURE
a) Phenolphthalein acidity (total acidity).
Take 50 ml or 100 ml of sample in an Erlenmeyer flask, add 0.15 to 0.5 ml (3 to 10 drops) of phenolphthalein indicator and titrate with standard 0.02 N NaOH to the same colour as that of the pH 8.3 NaHCO3, colour standard.
Calculations
mg/lit of phenolphthalein ml of 0.02 N.NaOH x 1000
or total acidity as CaCO3 = ml of sample
b) Methyl Orange or Mineral Acidity.
Take 50 or 100 ml of sample in an Erlenmeyer flask. Add 2 drops of methyl orange indicator to the sample and titrate with standard 0.02 N.NaOH to the very faint orange colour characteristic to pH 4.5.
Calculations
mg/lit of methyl orange or ml of 0.02 N.NaOH x 1000
mineral acidity as CaCO3 = ml of sample

NOTE:- If residual chlorine is present it is removed by addition of small amount (0.05 to 0.1 ml) of 0.1 N.Na2S2O3 to avoid interference with methyl orange colour change.
ALKALINITY
The alkalinity of a natural water is mainly due to the presence of carbonates, bicarbonates and hydroxides, and less frequently to borates, silicates and phosphates. Alkalinity is determined by titration with a standard solution of strong acid to certain end points as given by indicator solutions. Phenolphthalein contributed by hydroxide and carbonate and methyl orange or screened methyl orange is used for the second point (approximately pH 4-5) contributed by the bicarbonates.
REAGENTS
1. 0.02 N sulphuric acid.
2. Phenolphthalein indicator solution
3. Methyl orange indicator or SMO solution
PROCEDURE
a) Phenolphthalein alkalinity
Take 50 ml or 100 ml of sample in an Erlenmeyer flask, add 2 drops of phenolphthalein indicator, and titrate over a white surface with 0.02 N H2SO4 until the pink coloration just disappears.
Calculations:
mg/lit phenolphthalein ml of 0.02 N H2SO4 x 1000
alkalinity as CaCO3 = ml of sample
b) Total or methyl orange alkalinity
Take 50 ml or 100 ml of the sample. Add 2 drops of methyl orange indicator, and titrate with 0.02 N H2SO4 until the colour changes from yellow to faint orange.
Calculations :
mg/lit total or methyl ml of 0.02 N H2SO4 x 1000
orange alk. as CaCO3 = ml of sample
calculations of Hydroxide, Carbonate, Bicarbonate and total Alkalinity :
The different types of alkalinities are determined by using separately phenolphthalein and methyl orange as indicator for titration. The relative quantities of bicarbonate, carbonate, hydroxide and total alkalinity can be obtained from the following table :
Value of P & M Alkalinity
Bicarbonate Alkalinity
Carbonate Alkalinity
Hydroxide Alkalinity
Total Alkalinity
P = zero
M
Nil
Nil
M
P < 1/2 M
M - 2P
2P
Nil
M
P = 1/2 M
Nil
2P
Nil
M
P > 1/2 M
Nil
2(M-P)
2P - M
M
P = M
Nil
Nil
P
M

NOTE
1. If water is prechlorinated, add 2 drops of 0.1 N sodium thiosulphate solution, before addition of methyl orange indicator.
2. In the presence of alkali phosphates :
3. In the presence of phosphate treatment and where the phosphate is present as a trisodium salt, part of the alkalinity to phenolphthalein will be due to the alkalinity combined with the phosphate (PO4). If the phosphate content (as PO4) is expressed as mg/l; the effect on P will be equal to one half of the content in mg/l of phosphate and this shall be subtracted from P reading before using the above table. The alkalinity to phenolphthalein after addition of BaCl2 is not affected by the presence of phosphate.

PROCEDURE
To 100 ml of sample add a crystal of sodium sulphate and 10 of 10% BaCl2 solution. Mix well for 2 minutes and titrate using phenolphthalein as indicator.
Calculations
mg/lit of P (BaCl2) Value = ml of 0.02 N H2SO4 x 1000
ml of sample

FREE CARBON DIOXIDE
Free carbon dioxide is the term used to designate carbon dioxide gas dissolved in water. The designation "free" carbon dioxide is used to differentiate a solution of carbon dioxide gas from combined carbon dioxide present in the form of bicarbonate and carbonate ions. The CO2 content often is the sole contributor to the acidity of the sample.
REAGENTS
1. Standard 0.02 N NaOH solution
2. Phenolphthalein indicator solution
PROCEDURE
Collect the water sample in a glass bottle by allowing the water to flow from the bottom through a rubber tube connected to the source. Allow the water to overflow 2 to 3 times the capacity of the bottle and close. In the laboratory syphon the sample into 100 ml graduated cylinder and allow some over flow to take place. Quickly adjust the sample volume to 100 ml and add 0.25 - 0.5 ml (5 to 10 drops) phenolphthalein indicator. If the sample remains colourless titrate rapidly with standard NaOH to the colour of pH 8.3 NaHCO3 colour standard resting along side in an identical graduated cylinder. Repeat the determination on a second sample by adding full alkali volume of the first titration and if the sample remains colourless complete the titration. Accept the second titration as the more reliable results.
Calculations
CO2 as CO2, mg/lit = Titrant x N of NaOH x 1000 x 44
ml of sample
RESIDUAL CARBON DIOXIDE IN CATION EXCHANGER TREATED WATER
Residual carbon dioxide is normally checked in cation exchanger treated water or degasser outlet to check total anionic load on anion exchanger.
REAGENTS
1. 0.02 N standard sodium hydroxide solution
2. Phenolphthalein indicator solution
3. Methyl orange indicator solution
PROCEDURE
Collect the sample by means of rubber tubing discharging at the bottom of a graduated cylinder or nessler tube. Allow the sample to overflow for a few minutes and withdraw the tubing while the sample is flowing. Flick the cylinder to throw off excess sample above the 100 ml mark. To this 100 ml add methyl orange indicator and titrate against standard sodium hydroxide. To the second sample add enolphthalein indicator, and titrate against standard sodium hydroxide.
Calculations
Residual carbon dioxide in
decationized water mg. CO2/lit = (B-A) x 1000 x 0.88
100
Where B = ml of standard sodium hydroxide required for phenolphthalein end point
A = ml of standard sodium hydroxide required methyl orange end point
NOTE
1. The standard sodium hydroxide is rendered carbonate free by passing the solution through a strongly basic anion exchanger, Tulsion A-27 in the OH form.
2. Where the free carbon dioxide content of the water sample is high, some loss of CO2 occurs.

SODIUM BY FLAME PHOTOMETRY
Flame Photometry is concerned with the emission of characteristic radiation in flames by individual elements and the co-relation of the emission intensity with the concentration of the elements. A small volume of the solution of the sample is placed in a cup of an atomiser. Air or oxygen and a combustible gas are fed to the atomiser at controlled rates of flow and the solution is vaporised in a special burner. At the high temperature of the flame, the salts vaporise and dissociate into the constituent atoms or radicals. The vapours of the metal atoms are then excited atoms radiate their characteristic special line, the intensity of which is a relative measure of the metal in solution. This intensity is measured by suitable instruments.
REAGENTS
1. Standard Sodium Solutions for Calibration Curves :
Dissolve 2.5418 g of A.R. sodium chloride in 1 lit of distilled water in a volumetric flask. This solution contains the equivalent of 1.0 mg Na per ml. Dilute this stock solution to give four solutions containing 10, 5, 3 and 1 ppm sodium ions.
2. Standard Potassium Solution for Calibration Curves :
Dissolve 1.9090 g of A.R. potassium chloride in 1 lit of distilled water in a volumetric flask. This solution contains the equivalent of 1.0 mg/ per ml. Dilute this stock solution to give four solutions containing 10, 5, 3 and 1 ppm potassium ions.
PROCEDURE
The operating manual supplied with the instruments should be read before attempting any work. A general approach is described :
1. Adjust the sensitivity control to the minimum value.
2. Turn the gas supply and light the gas at the burner.
3. Adjust the air supply till a blue flame is obtained.
4. Charge the small sample beaker with distilled water and place it in position.
5. Fine adjustment of air supply so that the blue cone of the flame just forms ten separate cones, one to each burner hole.
6. Place the appropriate filter in position.
7. Spray standard solution containing the ion to be determined and by means of the calibrated potentiometer, adjust the galvanometer to read approximately full scale deflection.
8. Spray distilled water and adjust the galvanometer spot to read zero by means of the zero control.
9. Spray standard solution again and readjust the sensitivity control for full scale deflection of the galvanometer.
10. Check the zero by spraying with distilled water.
11. Spray solutions of known concentration but less than that of the standard solution, and note the galvanometer reading at each concentration. Plot the galvanometer reading against the concentration, expressed say as ppm and thus prepare a calibration curve for each element.
12. Spray the unknown solution in the flame. Note the galvanometer deflection and evaluate the concentration from the calibration curve.

NOTE: If it is known that the solution contains a sufficient concentration of an interfering substance to affect the reading it will be necessary to employ standard solutions which also contain approximately the same concentration of the interfering substance as is present in the sample. The ideal method of removing interferences is to separate the element being determined by chemical means, but this procedure is not always practicable.

HARDNESS
Hardness in water is due to the presence of bicarbonates, chlorides and sulphates of calcium and magnesium. Temporary hardness is due to the presence of bicarbonates and permanent hardness due to the presence of chlorides and sulphates. Sometimes, hardness may include iron, aluminium, zinc, manganese, etc.
METHOD A
COMPLEXAMETRIC METHOD (EDTA METHOD )
EDTA forms a chelated soluble complex when added to a solution of certain metal ions. If a small amount of EBT is added to an aqueous solution containing calcium and magnesium ions at pH of 10.0 + 0.1, the solution will become red wine. If EDTA is then added as a titrant, the calcium and magnesium will be complexed. After sufficient EDTA has been added to complex all the calcium and magnesium, the solution will turn blue from red wine.
REAGENTS
1. Ammonia buffer of pH 10.
2. M solution of disodium salt of ethylenediamine tetra acetic acid.
3. Eriochrome black T indicator solution.
PROCEDURE
Take 50 ml of sample in an Erlenmeyer flask, add 4 to 6 drops of Eriochrome black T indicator solution. Add 1 ml of buffer solution and mix. Titrate immediately with EDTA solution till the colour changes from red to blue.
Calculations:
Total hardness as CaCO3 mg/lit = Vol. of 0.01 M EDTA soln. x 1000
ml of sample
NOTE: For checking hardness in soft water use 500 ml of the sample into 750 ml evaporating dish and add 3 ml of buffer solution followed by 10-12 drops of indicator solution.

METHOD B
SOAP SOLUTION METHOD FOR HARDNESS TESTING
This is a quick method for checking hardness of treated water or an accurate determination of the hardness of treated water, EDTA method for hardness should be used.
REAGENTS
1. “B” soap solution
2. 40 ml shaking bottle
PROCEDURE
Take water sample upto 40 ml mark in shaking bottle. Add 10 drops of the "B" soap solution. Shake vigorously. If a lather is obtained which will last for 1 to 2 minutes, the water is soft. If no lather is obtained, or if the lather does not last, the water is hard.

NOTE
1. Rinse the shaking bottle clean with soft water thoroughly.
2. The soap solution bottle should be kept tightly stoppered. It will otherwise evaporate and give false reading.

CALCIUM HARDNESS
The water sample is titrated against EDTA solution using Murexide indicator (ammonium purpurate) in highly alkaline medium.
REAGENTS
1. Approximately 1 N sodium hydroxide solution
2. 0.01 M standard EDTA solution
3. Murexide indicator

PROCEDURE
Prepare a colour comparison blank in a white porcelain basin by stirring 2.0 ml of 1 N. NaOH, 0.2 g solid indicator mixture (or 4 to 6 drops of indicator solution) into 50 ml of distilled water and sufficient EDTA titrant (0.05 to 0.1 ml) to produce an unchaning purple colour. Pipette into a similar basin 50 ml. of sample, neutralize the alkalinity with 0.02 N. HCl, boil for 2 to 3 minutes to expel the CO2 and cool to room temperature. Add 2.0 ml 1 N NaOH, or a volume sufficient to produce a pH of 12 to 13 and mix. Add 0.2 g of powdered indicator. Stirring constantly titrate with standard EDTA solution to the colour of comparison blank. Check the end point by adding 1 or 2 drops of titrant in excess to be sure that no further deepening of the purple colour takes place.
Calculations
Calcium, as CaCO3, mg/lit = (A-B) x C x 1000
ml of sample
Where A = ml of EDTA required for titration of sample
B = ml of EDTA required for blank
C = mg of CaCO3 equivalent to 1.0 ml of EDTA

NOTE: The only serious interference with the EDTA titrant of calcium is that of orthophosphate ion. If the calcium hardness exceeds about 60 ppm CaCO3, and the concentration of orthophosphate is 10 ppm, or more, calcium phosphate is precipitated when the pH is raised to 12, giving low results. Phosphate, if present, can be removed by ion exchange.

IRON: Iron is frequently found in natural waters. In addition to the "natural" iron content of a water, iron is passed into solution when the corrosion of iron and steel surface occur.
METHOD A
O-PHENANTHROLINE METHOD
The calorimetric estimation of iron is based on the formation of the orange red phenanthroline complex (C12 H2 N2)3 Fe++ in the pH range 2-9. Below pH 2 the colour develops slowly and is much weaker. Since this complex is formed with ferrous iron Hydroxylamine, hydrochloride is the most satisfactory reducing agent (for the reduction of ferric iron). Certain divalent metals such as Cd, Hg and Zn form slightly soluble complexes with the reagent and reduce the intensity of the iron colour, but, this interference may be minimised by adding a large excess of reagent. Phosphorous may be present upto 20 ppm. Fluoride (500 ppm) does not interfere if the pH is kept above 4.0.
REAGENTS
1. Standard iron solution
2. 1-10 phenanthroline monohydrate REAGENTS
3. Ammonium acetate buffer solution
4. Hydroxylamine hydrochloride

PROCEDURE
For total iron use well mixed sample. For determination of dissolved iron if precipitated iron is present, decant a sample allow to settle down the precipitations and filter. If precipitated iron is present, use the filtrate. Prepare a series of visual standards/photometric calibration curve by measuring the following amounts of standard iron solutions into beakers, 0.01, 0.02, 0.03, 0.04, 0.05 upto 0.1 mg. Dilute the solution to 50 ml. To the sample, blank and the standards add 2 ml conc. HCl, 1 ml hydroxylamine solution, glass beads and boil until the volume is reduce to 15 to 20 ml. Transfer the solution to Nessler tubes if visual comparison is to be made or to 50 or 100 ml volumetric flasks if spectrophotometric method is used. Add 10 ml ammonium acetate buffer and 5 ml 1-10 phenanthroline reagent, dilute to the mark with distilled water, and mix well. After 10 to 15 minutes compare the colour visually or measure the absorbance at 510 mm. The colour forms in the range of pH 2-9 and is very stable.
Calculation
Iron as Fe, mg/lit = mg of Fe x 1000
ml of sample
METHOD B
IRON BY THIOGLYCOLLIC ACID METHOD
In ammoniacal medium, mercaptoacetate (as the ammonium salt HSCH2 COONH4) reacts with iron to yield the soluble red purple product Fe (OH) (SCH2COO)2 containing iron in the ferric state. Ferrous iron reacts to give the same complex by air oxidation. In the absence of oxygen, the colour slowly fades as a result of the reduction of ferric iron to ferrous and oxidation of mercaptoacetate to the disulphide - O2 CCH2 SSCH2CO2. The air oxidation of ferrous iron in the system is very rapid and usually under analytical conditions, more than the pace of the reduction so that a stable coloration is obtained. The reaction must be carried out in basic medium, precipitation of metal hydroxides may be prevented by adding citrate. Certain metals among them Cu (21 mg), Arsenic +3 (> 100 mg), Tin+2, Zinc (> 10 mg) and cadmium black, the iron colour, although this effect can be diminished by the addition of more reagent. Very high concentration of salts of alkali metals decrease the colour intensity somewhat. On the other hand anions have but a slight effect on the colour. As much as 5000 ppm chloride, fluoride, orthophosphate, tartrate, oxalate and citrate do not interfere. The colour is fairly stable (atleast 6 hours in diffuse light).
REAGENTS
1. Thioglycolic acid (80%)
2. Ammonia solution (sp. gr. 0.91)
PROCEDURE
Take 100 ml of water sample into a 250 ml beaker. Add 2.5 ml of thioglycollic acid reagent. After stirring evaporate in sand or water bath to 5 ml (not less), then allow to cool. Add 5.0 ml of ammonia solution, shake and pour into the 25 ml measuring flask. Make upto the mark. Measure optical density at 540 mm using 5 cms cell. Reagent blank and standard to be carried simultaneously.
Calculations
Iron as Fe, mg./lit = mg. of Fe x 1000
ml. of sample
SILICA
The silica content of natural water will vary to a considerable extent depending on the locality. The presence of silica is particularly objectionable in water used for boiler feed purpose as it may lead to the formation of hard dense scale. In addition, a very serious problem encountered in high pressure operations is the deposition of siliceous materials on turbine blades & super heaters. The gravimetric method is the standard applicable above 20 mg / lit SiO2 content . This method should be followed for standardisation of standard silicate solution used in colometric methods. The heteropoly blue colometric method is adaptable for the range of 0 to 2 mg / lit SiO2 & yellow molyb silicate method in the range of 0 to 20 mg / lit . Reagent blank should always be used in all the three methods.
METHOD A
GRAVIMETRIC METHOD
PROCEDURE
Take a sample to contain atleast 10 mg of SiO2 . If necessary clarify by filtration. Acidify with 2 or 3 ml of conc. Hcl & evaporate to dryness in a platinum dish on a water bath . At regular intervals add 2 or more portions of 2 to 3 ml of conc. HCl as additional quantities of sample is added to the dish. Bake the evaporated residue in an oven ad 110 Deg. C for about an hour. Add 5 ml. of conc. Hcl warm & add 50 ml distilled water. Loosen the clinging residue from the sides & the bottom of the dish & filter collecting the filtrate. Wash the dish & residue with hot 1 : 50 HCl & finally with distilled water until the washings are free from chloride. Return the filterate & washings to the platinum dish & again evaporate to dryness. Repeat as previously, collecting the residue in another filter paper. Dry the two filter papers with residue ,burn, ignite at 1000-1200 Deg C in a platinum crucible & weigh . Moisten the residue with a few drops of distilled water , add 2 drops of H2SO4 & 10 ml. 48% HF . Cautiously evaporate to dryness on a steam bath in a fume cupboard . Again ignite at 1000-1200 Deg. C. Cool & weigh. Carry out a blank.
Calculations
( A - B ) - ( C - D ) x 1000
SiO2, as SIO2 mg / lit = ml of sample

Where A = Weight of crucible & sample residue in mg. after first ignition
B = Weight of crucible & sample residue in mg. after HF treatment & second ignition.
C = Weight of crucible & blank residue in mg. after first ignition
D = Weight of crucible & blank residue in mg. after HF treatment & second ignition.

METHOD B
REACTIVE SILICA
COLOMETRIC ESTIMATION OF SILICA
Ammonium molybdate at approximately pH 1.2 reacts with silica & any phosphate present to produce hteropoly acids. Oxalic acid is added to destroy the molybdophosphoric acid but not the molybdosilicic acid . Even if phosphate is known to be absent , the addition of oxalic acid is highly desirable & is a mandatory step . The intensity of the yellow colour is proportional to the concentration of molybdate- reactive silica. The yellow molybdosilicic acid is reduced by means of 1 amino - 2- naphthol - 4 - sulphonic acid to heteropoly- blue. The blue colour is more intense than the yellow colour & provides increased sensitivity. In atleast one of its forms , silica does not react with molybdate even though it is capable of passing through filter paper & is not noticeable turbid. The presence of such a molybdate unreactive silica is undesirable in raw water .It will not be removed in the water treatment plant & will find its way to highly pressure stream system , where it will be converted to " molybdate-reactive " silica. Such increase in silica content will give rise to scale problem .
Chromate & large amounts of fe, PO4, sulphide, tannin, colour & turbidity are potential interferences. Oxalic acid treatment suppresses PO4 & reduces tannin interference. Inorganic sulphide can be removed by boiling an acidified sample. The addition of 1 ml. of 1% EDTA solution after molybdate reagent overcomes high Fe & Ca concentrations.

COLOMETRIC ESTIMATION OF SILICA - 0- 20 PPM SiO2
REAGENTS
1. Ammonium molybdate solution
2. 2 N sulphuric acid.
3. 10 % oxalic acid.
4. Lovibond comparator with standard silica disc.
PROCEDURE
1. Fill one of the Nessler tubes to the 50 ml. mark with sample & place in the left hand compartment of Lovibond comparator.
2. Fill the other Nessler tube with 50 ml. of sample at 25 - 30 Deg. C . Add 2 ml. of acidified ammonium molybdate solution . Mix thoroughly, add 4 ml. of oxalic acid & again mix thoroughly. Place in the right hand compartment & allow to stand for 10 minutes.
3. Stand the comparator facing a uniform source of light, compare the colour of the sample in the disc. Rotate the disc until the colours are matched.
Calculations
SiO2 in mg / lit as SiO2 = Disc reading x 20
NOTES
1. Should the colour in the test solution be deeper than the deepest standard , a fresh test should be carried out using a smaller quantity of sample & diluting to 50 ml. with distilled water before adding the REAGENTS.
2. Silica free water :
3. Distilled water from an all - metal "Still " or water which has been passed successively through a mixed bed deionisation unit & strongly basic anion exchanger such as Tulsion A27MP unit regenerated with a regeneration level of 320 gm per litre NaOH has been found to be suitable. Prepare & store in a polyethylene bottle a large batch of water containing not more than 0.005 ppm SiO2 , determine the silica content of water by treating it as a sample . This water is used to prepare reagents & standards , & to dilute samples when necessary .

COLOMETRIC ESTIMATION OF SILICA 0-2 PPM SiO2
REAGENTS
1. Acidified ammonium molybdate solution.
2. 10 % oxalic acid.
3. Amino - naphthol reducing agent.
4. Lovibond comparator with standard silica disc or spectrophotometer suitable for measurement at 815 microsiemens wave length .
PROCEDURE
1. Fill one of Nessler tubes to the 50 ml . mark with sample, & place in the left hand compartment of Lovibond comparator.
2. Fill the other Nessler tube with 50 ml. of sample, at 25 -30 Deg.C. Add 2 ml. of acidified ammonium molybdate solution . Mix thoroughly, stand for 5 minutes . Add 4 ml of oxalic acid & mix well . Then 2 ml. of reducing agent, mix well compared with that of a blank comprising the same water without reagents, using Lovibond comparator or read the absorbance using a spectrophotometer (wave length 815 microsiemens). Compute the silica content from the standard graph prepared from the standard silica solution.
METHOD C :
DETERMINATION OF TOTAL SILICA (MOLYBDATE REACTIVE & UNREACTIVE SILICA )
The molybdate unreactive silica is converted to the reactive form or state by digesting the sample with sodium bicarbonate.
REAGENTS
1. Sodium bicarbonate .
2. 1 N sulphuric acid.
3. Other reagents as per previous method.
PROCEDURE
Take 100 ml. of sample or lesser quantity (20 - 100 micrograms SiO2) but made upto 100 ml. distilled water in a platinum dish. add 200 mg. silica free sodium bicarbonate & digest on a stream bath for one hour . Cool & add slowly , with stirring , 2.5 ml. sulphuric acid ( 1 N ) . Do not interrupt the analysis but proceed at once with the remaining steps . Transfer quantitatively into a plastic container. For development of colour & Calculations refer the previous procedure.
SULPHITE
The determination of sulphite usually is made only on boiler water. Generally speaking, sulphite is not present in natural water. In boiler, feed water sodium sulphite is fed to remove dissolved oxygen .
REAGENTS
1. Hydrochloric acid 1 + 1
2. Starch Indicator Solution:-Dissolve 5 gms of starch & 0.01 gms. of mercuric iodide with 30 ml. cold distilled water & slowly pour it with constant stirring in to 1 lit. of boiling distilled water. Boil for 3 minutes. Allow to cool & decant off supernatant clear liquid .
3. Standard Potassium Iodate:- Iodine Solution :Weigh accurately 0.713 gms. of potassium iodate & dissolve in about 150 ml. of distilled water. Add 7 gms of potassium iodide & 0.5 gms. of sodium bicarbonate. When dissolved, dilute the solution to exactly 1 litre.
PROCEDURE
Place 10 ml. of 1 +1 HCl in a 250 ml. flask. Rapidly add 100 ml sample, submerging the pipette tip below the acid surface to minimise air exposure . After adding 1 ml. starch indicator solution titrate with standard iodate - iodide ( KIO3 ) solution ,to the first appearance of persistent blue colour. Determine the blank titration by taking 100 ml. distilled water .
Calculations
Sulphite as SO3 , mg / lit = ( A - B ) x 100
Where , A = ml of titrant for sample
B = ml of titrant for blank
STANDARD IODATE- IODIDE SOLUTION
Weigh accurately 0.713 g of potassium iodate & dissolve in about 150 ml of distilled water. Add 7 g of potassium iodide & 0.5 g of sodium bicarbonate when dissolved dilute the solution to exactly 1 lit.
SULPHATE METHOD A
GRAVEMETRIC METHOD
The sulphate is precipitated as barium sulphate by the addition of barium chloride to a slightly acidified solution of the sample at the boiling temperature. The precipitate is ignited and the residue is weighed as barium sulphate. The presence of silica and other non-volatile suspended matter cause high results. Sulphites and iron should also be present.
REAGENTS
1. Hydrochloric Acid 1:1
2. Methyl Red Indicator solution
3. Barium Chloride solution
PROCEDURE
Take sample to contain approx. 50 mg sulphate. Dilute to 250 ml. Adjust the acidity with HCL to Ph 4.5 to 5.0, using methyl red indicator . Then add an additional 1 to 2 ml. of HCL. Heat the solution to boiling and stir gently then add warm Bacl2 solution slowly until precipitation appears to be complete then add about 2 ml. in excess. Digest the precipitate on a water bath at 80 to 90 deg C, not less than 2 hours. Filter through a filter paper or through gooch crucible and wash with hot distilled water until washings are free from chlorides. Dry the filter paper and precipitate and ignite at 800 deg. C for 1 hr. Do not let the filter paper flame. Cool in a desicator and weigh.
Calculation
Sulphate as SO4 mg/lit = mg BaSO4 * 411.5
ml. of sample


METHOD B
EDTA METHOD
A measured excess of standard barium chloride solution is added to the sample & the excess barium chloride estimated by titration against standard EDTA solution.
REAGENTS
1. Approx. 1N nitric acid
2. Standard barium chloride solution.
3. pH-10 buffer solution.
4. EBT indicator.
5. 0.01 M EDTA solution
PROCEDURE
Neutralise 100 ml. of the sample with dilute nitric acid, adding a slight excess , & boil off to expel carbon dioxide. Add 10 ml. or more if required, of standard barium chloridesolution to boiling solution & allow it to cool. Dilute to 200 ml. mix & allow precipitate to settle. Withdraw 50 ml. of the supernatant liquid, add 0.5 ml. to 1.0 ml. of buffer & several drops of indicator solution. Titrate with standard EDTA solution to a blue colour which does not change on addition of further drops of EDTA solution.
Calculations
sulphates, as SO4, mg/lit = 9.6 (0.1A+B - 4C )
where:
A = Total hardness of sample (as CaCO3 mg/lit )
B = Volume in ml. of standard barium chloride solution added
C = Volume in ml. of standard EDTA solution required for titration
NOTE:
1. It is very difficult to judge the endpoint of titration of barium against EDTA using EBT as indicator. It is preferable to use standard MgCl2 solution along with BaCl2 for Bacl2 standardisation ( or use a mixture of BaCl2 + MgCl2 solutions, instead of BaCl2 solution for precipitate of sulphate ion ).
2. It is also desirable to add MgCl2 solution, whenever, sample is low in Mg ions as in the case of decationized water.
CHLORIDE
METHOD A
SILVER NITRATE METHOD
Chloride is determined by titration with std. silver nitrate solution in the presence of potassium chromate indicator at neutral Ph. Silver chloride is precipitated and at the end point red silver chromate is formed.
REAGENTS
1. N Std. silver nitrate solution
2. Potassium chromate indicator
3. Phenolthalein Indicator solution
4. N Nitric Acid solution
5. Calcium carbonate
PROCEDURE
Take 50 ml. or 100 ml of sample in an Erlenmeyer flask. Add five drops of phenolthalein. If the sample turns pink, Neutralise with 0.02 N Nitric acid. If Acidic (as in the case of decationised water) add a small amount of A.R. calcium carbonates. Add 1 ml of potassium chromate indicator and titrate with std. silver nitrate solution with constant. stirring until there is perceptible reddish colour. Subtract 0.2 ml. from titration fig. to allow for the excess of reagents required to form silver chromate.
Calculation
Chloride as CaC03 mg/lit = ml of AgN03 * 1000
ml of sample taken
NOTE
1. If sample is highly coloured , add AL(OH)3 suspension, mix then let it settle , filter and combine filtrate and washing
2. If sulphide, sulphite and thiosulfate is present, add 1ml H2O2 and stir for 1 Min.
3. Bromide, iodide and cyanide register as Eqvt. chloride concentration.
METHOD B
Chloride ion can be titrated with mercuric nitrate because of the formation of soluble, slightly dissociated mercuric chloride. In the Ph range 2.3 to 2.8 diphenylcarbozone indicates the end point of this titration by formation of purple complex with excess of mercuric ions. To keep the solution in Ph range +/- 0.1 Ph unit nickel nitrate with HNO3 is added .
REAGENTS
1. 0.02 N Mercuric nitrate Std. solution
2. Diphenyl-carbozone indicator solution
3. 4 M nickel nitrate solution
PROCEDURE
Take 50 ml. of sample , add 1 ml. of diphenylcarbozone indicator solution. Add 1 ml. of nickel nitrate solution. Titrate against Std. mercuric nitrate solution to colour change of green to violet. Carry out blank titration with DM Water.

Calculation
Chloride as CaCO3 mg/lit = (A - B ) * 1000
ml. of sample
where , A = ml of titrant required for sample
B = ml of titrant required for blank.
METHOD C
CHLOROMETRIC METHOD FOR CHLORIDE (MERCURY THIOCYNATE METHOD)
This method depends upon the displacement of thiocynate ion from mercuric thiocynate by chloride ion. In the presence of ferric ion, a highly coloured ferric thiocynate complex is formed and the intensity of its colour is proportional to the original chloride ion concentration.
REAGENTS
1. Mercuric thiocynate solution
2. Ferric ammonium sulphate solution
3. Std. sodium chloride solution -0.1 mgCl / ml.
PROCEDURE
Take 10-20 ml of water sample containing about 40 micrograms of chloride in a 25 ml. std. flask. Add 2.0 ml of ferric ammonium sulphate solution, followed by 2.0 ml of mercuric thiocynate solution. Make up to the volume. Measure the optical density at 460 microsiemens From the calibration curve for the Std., compute the value for the sample.
Calculation
Chloride , as Cl mg /lit = Microgram of chloride from graph
ml. of sample
PHOSPHATE
A neutralised sample is reacted with ammonia molybdate & stannous chloride. The blue colour obtained is matched against that produced with a series of standard phosphate solutions, visually or with spectrometer at 690 micro.
REAGENTS
1. Phenolphthalein Indicator solution.
2. Approximately 4 N sulphuric acid.
3. Ammonium Molybdate solution.
4. Stannous chloride solution.
5. Standard phosphate solution.
PROCEDURE
To a 50 ml. sample containing not more than 0.15 mg. of phosphate (as PO4), add one drop of phenolphthalein indicator. If a pink colour is obtained, add dilute H2SO4 dropwise to discharge the colour. Add, with through mixing after each addition 2.0 ml. of ammonium molybdate solution & 0.25 ml. 5 drops of stannous chloride solution. The rate of colour development & intensity of colour depend upon the temperature of the final solution, each 1 Deg C increase producing about 1 percent increase in colour. hence samples & reagents should be within 2 deg . C of one another & at a temperature between 20 to 30 deg. C. After 10 min. but before 15 min., measure the colour photometrically or visually in a Nessler tubes against standards prepared simultaneously. A blank shall always be run on the reagents & distilled water.
Calculations
Phosphates as PO4 mg/lit = 1000 * w
V
where,
w = weight in mg. of phosphate (as Po4) in sample from standard graph (or solution).
V = Volume in ml. of sample taken.

OXYGEN CONSUMED FROM PERMANGANATE SOLUTION
(CHEMICAL OXYGEN DEMAND)
This method is only an empirical measure of the organic matter. It gives some indication of the nature of the oxidisable substance present in the sample since nitrates, ferrous salts or sulphides will reduce the permanganate immediately whereas the organic matter reacts with the permanganate only after some time.It can be determined at room temperature by estimating the amount of standard KMnO4 solution consumed by the sample in 4 hours or at elevated temperature for a shorter period.
REAGENTS
1. N/10 standard KMnO4 solution.
2. N/10 standard oxalic acid solution.
3. (1: 3) sulphuric acid solution
PROCEDURE
Take 100 ml. of sample in conical flask. Add 10 ml. of 1:3 sulphuric acid solution & 10 ml. of N/10 standard KMnO4 solution is added to acidified sample. The sample is then boiled for exactly 10 min. Introduce 10 ml. of standard N/10 oxalic acid & while still hot titrate with standard KMnO4 slightly pink colour reappears
Calculations
Oxygen as KMnO4 consumed, mg/lit = ml. of KMnO4solution used up * 31.6
or
Oxygen, as Oxygen mg/lit = ml. of KMnO4 solution *8.0
OILS AND GREASE
OUTLINE OF THE METHOD
The oils & grease are extracted by an organic solvent . The solvent is distilled off & the weight of the extracted matter is determined. Some extractable, especially unsaturated fats & fatty acids, oxidize rapidly hence, special precautions regarding temperature & solvent vapour displacement are necessary to minimise this effect.
SAMPLING
The most satisfactory method of sampling two - phase liquids is to use a sampling tube that is capable of withdrawing a complete section of the water as it flows in a rectangular culvert or trough, in most instances, however, water will have to be sampled from the outfall of the pipe or from a stream & in these circumstances some of the water should first be collected in a large cylindrical vessel having a capacity of 10 to 15 litres. A sectional sampling tube should be used to withdraw the test sample from this. A sampling tube suitable for sampling water, that don’t contain highly viscous matter ( for example, tar ) consist of a heavy - gauge brass tube , 1m. long , with an outside diameter of 40 mm. Over one end of the tube is fitted to the brass bucket made from a piece of tube 50 mm. long & sealed at one end. The bucket has an internal diameter of 1.5 mm. greater than the outside diameter of the main tube. To the opposite sides of the bucket, are braced two brass rods, 6mm. in diameter , which pass through guides braced to sides of the main tube. The rods are so arranged that the top of the bucket can be withdrawn to a distance of not less than 10 cm. from the bottom of the main tube, & they guide the bucket into a position covering the end of the tube when it is pushed back again.
A suitable spring catch is provided on one of the guide rods so that the bucket is automatically locked into the top position when it is raised to its highest point . The open end of the sampling tube is fitted with a rubber bung. To take a sectional sample , the spring catch is released & the bucket is drawn as far away as possible from the end of main tube. The rubber bung is withdrawn from the other end. The tube is lowered vertically through the liquid to the sampled until the bottom of the bucket rest on the bottom of the culvert or of the vessel that has been filled with the water. The main tube is then pushed down, guided by the brass rods, to the limits of his travel, whereupon the spring catch locks the bucket in the raised position covering the end of the tube. The rubber bung is tightly inserted in the open end & the tube is withdrawn.

The outside of the sampler is wiped free of adhering liquid the bucket & the lower part of the tube are inserted into a wide - mouthed bottle of suitable capacity, & the rubber bung is removed. The sample section of the liquid will flow into the bottle leaving a small quantity of liquid in the bucket . The tube is then tilted , so that this liquid is added to the main bulk of the sample. The operation is repeated until sufficient quantity has been collected. At least 24 - 25 mm. of air space should be left between the top level of the liquid & the stopper of the bottle.


STORAGE OF SAMPLE
Since many oils & hydrocarbons are utilised by bacteria , storage is obviously detrimental. However, if it becomes necessary to store the sample before analysis is taken up , the samples should be acidified with dilute sulphuric acid (1:1 ) , 5 ml / lit., of the sample, to inhibit bacterial activity .
APPARATUS
SEPARATING FUNNELS
Of 1.5 to 2 litres capacity . The stopper or stop or stop cock should not be lubricated with matter soluble in petroleum ether.
REAGENTS
1. Dilute Hydrochloric acid - 1 : 1
2. Light Petroleum (Petroleum ether) - boiling range 40 to 60C.
PROCEDURE
Place the sample, usually 1 litre, in a separating funnel of sufficient size to allow the addition of acid & solvent , & still have space for proper agitation. Acidify the sample with dilute hydrochloric acid, 5 ml /lit, of the sample. Rinse the sample bottle carefully with 15 ml. of petroleum ether & add the ether washings to the separating funnel. Add an additional 25 ml. of ether to the sample bottle, rotate the ether in the sample bottle & add the ether to the separating funnel . Shake vigorously for 2 minutes . Allow the ether layer to separate. Withdraw the aqueous portion of the sample into a clean container , & transfer the solvent layer into a clean, tarred distilling flask capable of holding at least 3 volumes of solvents(See Note).If a clear ether layer cannot be obtained, filter the solvent layer into tarred distilling flask through a funnel containing an ether moistened filter paper. The filter paper should be washed with petroleum either after folding to avoid inclusion of skin oils. Use a small funnel and filter paper as practical.
NOTE: While transferring the solvent layer from the separating funnel, a small quantity of it remains at the stem of the separating funnel, it is advisable to wash it with a few millilitre’s of solvent and to add the washings to the solvent layer. Return the aqueous portion of the sample to the separating funnel, rinsing the container with 15 ml. of ether. Add the ether washings and additional 25 ml. of ether to the separating funnel and agitate for about 2 Min. Allow the solvent layer to separate and discard the aqueous phase. Add the ether washings to the tarred distilled flask . After all the ether from the 2 extractions and the final rinsing are included wash down the funnel and filter paper twice with fresh 5 ml. increments of the petroleum ether.
Distil of all but approx. 10 ml. of the ether extract on a water batch or an electric heating mantle, observing necessary safety precautions and keeping the heat source at about 70 Deg c. Disconnect the condenser and boil of the remaining the solvent from the tarred flask at the same temp. Dry on a water bath or stream bath. When dry ,lay the flask on its side to facilitate the removal of solvent vapour. Introduce Aprrox. 3 volumes of dry illuminating gas or Nitrogen into flask to displace solvent vapour . Cool in desiccator for 30 Min. and weigh.
Calculation
Oils And grease , mg/lit = 1000 W
V
Where,
W = weight in Mg. of the residue in the flask
V = volume in ml. of the sample taken for the test.
Express the result to the nearest Mg
RESIDUAL CHLORINE
(ORTHOTOLYDINE - ARSENI METHOD)
Chlorine rapidly oxidises ortholydine (3,3-dimethybenzdine) to the corresp. hologuinone which is intensely yellow. This provides a sensitive test for available chlorine. The test is subject to interference by production of false colour for chlorine when nitrite ,iron or manganese is present in the water. The false colour produced with orthotoludine by interfering substance present in the presence of sodium arsenite but the colour due to residual chlorine does not. The test permits the measurement of the relative amounts of free available chlorine, combined available chlorine ,and colour due to interfering substances. The temperature of the sample should never be above 20 deg C.
REAGENTS
1. Phosphate buffer solution -0.5%
2. Potassium dichromate solution
3. P-Tolydine reagent
4. 5 % sodium arsenite solution
PROCEDURE
1. VISUAL STANDARDS:- Pipette into 100 ml. Nessler cylinder 1,2,3 etc. ml of dilute chromate- dichromate solution an dilute to 100 ml with phosphate . Protect the solutions from dust, evaporation and direct sunlight. These Stds. correspond to residual chlorine Eqvt. of 0.01, 0.02 ,0.03.... mg/lit Resp.
2. FREE AVAILABLE CHLORINE:-In a nessler tube take 0.5 ml of Toludine reagent and 9.5 ml of sample . Mix quickly and thoroughly and add 0.5 ml of NaAS02 followed by mixing. Compare the colour with Std. (Call this reading as A).
3. TOTAL AVAILABLE RESIDUAL CHLORINE:- In a nessler tube take 0.5 ml of 0-Toludine reagent and 9.5 ml of sample, mix and compare the colour with standards colour in similar tube after 5 Min. (Call this reading as B).
4. BLANK:-Prepare a blank 9.5 ml sample and 0.5 ml NaAS02 solution and compare the colour with std. colour immediately and after 5 Min. (Call this reading as C1 and C2).
Calculation
Free available residual chlorine = Reading A - Blank C1
Combined available residual chlorine = Reading B - Blank A
Total available residual chlorine = Reading B - Blank C2
REAGENTS
1. STANDARD 1 N HCL SOLUTION :- Dilute 83 ml. of conc. HCL (about 11 N solution, specific gravity 1.174-1.189 ) to 1lit. with distilled or deionised water . Standardise with standard sodium carbonate solution.
2. STANDARD 0.1 N HCL SOLUTION :-Dilute 8.3 ml. of conc. Hcl or 100 ml. of 1 N solution to 1000 with distilled water. Standardise with standard sodium carbonate solution.
3. STANDARD 0.02 N Hcl SOLUTION. :-Dilute 200 ml. of 0.1 N standard acid to 1000 ml. with distilled water. Standardize with standard sodium carbonate solution
4. STANDARD 1 N H2SO4 SOLUTION :-Dilute 28 ml. of conc. H2SO4 (about 36 N solution, specific gravity 1.834-1.836 ) to 1lit. with distilled or deionised water. Standardise with standard sodium carbonate solution.
5. STANDARD 0.1 N H2SO4 SOLUTION
Dilute 2.8 ml. conc. H2SO4 to 1 lit. with distilled or deionised water. Standardise with standard sodium carbonate solution.
6. STANDARD 0.02 N H2SO4 SOLUTION:-Dilute 200 ml. of 0.01 N H2SO4 to 1 lit. with distilled or deionised water. Standardise with standard sodium carbonate solution.
7. 1.0 N HNO3 SOLUTION :-Dilute 64 ml. of conc. HNO3 (about 15 N solution, specific gravity 1.409-1.418) to 1lit. with distilled or de ionised water. Standardise with standard sodium carbonate solution.
8. STANDARD I.0 N NAOH SOLUTION:-Dissolve 40.0 gm. of NAOH to 1.0 lit. with carbon dioxide free distilled or deionised water . Standardise with standard acid solution.
9. STANDARD 0.1 N NAOH SOLUTION:-Dissolve 4.0 gms of NAOH to 1.0 lit. with carbon dioxide free distilled or deionised water. Standardise with standard acid solution.
10. STANDARD SODIUM CARBONATE SOLUTION:-(Approx. 0.05 N ) Dry 3 to 5 g primary standard Na2 CO3 at 250 deg C for 4 hours & cool in a desiccators. Weigh 2.5 +/- 0.2 gms (to the nearest mg) Dilute to 1litre with deionised or distilled water.
11. STANDARD 0.02 N SILVER NITRATE SOLUTION.:-Dissolve 3.3927 gms. AgNO3 in distilled water & dilute to 1 lit. Standardise against 0.02 N NaCl standard solution.
12. STANDARD 0.02 N SODIUM CHLORIDE SOLUTION :-Dry 2-3 g of primary standard NaCl at 140 deg C for 4 hours & cool it in a desiccators. Weigh 1.689 gms (to the nearest mg. ) Dilute to 1litre with deionised or distilled water.
13. STANDARD 0.02 N MERCURIC NITRATE SOLUTION:-Dissolve 3.246 gm. mercuric nitrate in 100 ml of 5% HNO3 solution & make up to 1 lit. with D.M. water. Standardise with standard sodium carbonate solution.
14. STANDARD MERCURIC THIOCYANATE SOLUTION :-Weigh 1 gm Hg(SCN) 2 & add 100 ml methanol & mix to obtain a saturated solution. store in a amber bottle in a cool place.
15. FERRIC AMMONIUM SULPHATE:-Dissolve 12 g of Fe (NH4)2(SO4) 2. 12H2O in 100 ml of 9 N HNO3 (580 ml. of conc. HNO3 in 1 lit. of water ). Filter if necessary & store in a amber bottle.
16. 0.1 MG/LIT. STANDARD CHLORIDE SOLUTION:-Dissolve 1. 1648 g NaCl in 1 lit. of distilled or deionised water.
17. AMMONIA BUFFER OH pH 10:- Dissolve 16.9 g of ammonium chloride in 143 ml. conc. ammonium hydroxide (NH4OH). Add 1.25 g of magnesium salt of EDTA. (If the magnesium salt of EDTA is unavailable dissolve 1.179 g disodium salt of EDTA & 780 mg. MgSO4.7H2O or 644mg. MgCl2.6H2O in 50 ml. distilled water.) & dilute to 250 ml. with distilled water.
18. STANDARD 0.01 M SOLUTION OF EDTA:-Dissolve 3.723 g of disodium salt of EDTA in 1 lit. of distilled or deionised water. Standardise with standard calcium solution.
19. STANDARD CALCIUM SOLUTION:-Weigh 1 gm anhydrous calcium carbonate into a beaker, add a little at a time, dilute Hydrochloric acid until CaCO3 has dissolved. Wash down the beaker with carbon dioxide free water & makeup to 1 lit. 1 ml. of the solution contains 1mg of sulphate (as SO4)
20. STANDARD BARIUM CHLORIDE SOLUTION:-Dissolve 2.443 g of barium chloride (BaCl2, 2H2O) in distilled water & dilute to 1 lit. 1 ml. of this solution is equivalent to 0.36 mg. of sulphate (as SO4).
21. STANDARD POTASSIUM IODATE -IODATE SOLUTION:-Weigh accurately 0.713 g of potassium iodate & dissolve in about 150 ml. of distilled water. Add 7 g of potassium iodate & 0.5 g of sodium bicarbonate ,when dissolved, dilute the solution to exactly 1 liy.
22. STANDARD IRON SOLUTION:-Dissolve 1.404 g of ferrous ammonium sulphate Fe(NH4)2(SO4)2, 6H2O in 50 ml. distilled water & 20 ml. conc. H2SO4. Add 0.1 N KMNO4 dropwise to impart a faint but persistent pink colour & dilute to 1 lit. with distilled eater. Dilute 50 ml. of the above stock solution to 1 lit. with distilled water to form a standard solution containing 0.01 mg. fe/ml.
23. 1,10 PHENANTHROLINE MONOHYDRATE SOLUTION:-Dissolve 0.1 g in 100 ml. distilled water containing 2 drops conc. Hcl . (Not more than 0.1 mg. Fe can be determined).
24. AMMONIUM ACETATE BUFFER SOLUTION:-Dissolve 250 g of ammonium acetate in 150 ml. distilled water, add 700 ml. glacial acetic acid & dilute to 1 lit.
25AMMONIUM MOLYBDATE SOLUTION FOR SILICA ESTIMATION:-75 g of ammonium molybdate is dissolved in 500 ml. of distilled water. To 322 ml. of 10 N sulphuric acid molybdate solution is added gradually with constant stirring. The solution is made upto 1 lit.
26. 10% OXALIC ACID:-Dissolve 10 gms. oxalic acid in 100 ml. of distilled water.
27. AMINO NAPHTHOL REDUCING AGENT :-Dissolve 0.5 g of 1 amino-2-naphthol-4sulphonic acid & 1gm. of sodium sulphite (Na2SO3) in 50 ml. distilled water, with gentle warming if necessary, add this to solution of 30 g sodium metabisulphite (NaHSO3)in 150 ml. distilled water. Filter into plastic bottle. Dicard the solution when it becomes dark. prolong reagent life by sorting in a refrigerator.
28. STOCK SILICA SOLUTION:-Dissolve 4.73 g of sodium metasilicate nonhydrate (Na2SiO3, 9H2O) in recently boiled & cooled water & dilute to approx. 900 ml. Analyse 100.0ml. portions by gravimetric method, adjust the remainder of the solution to contain 1.000 mg./1SiO2. Store in a tightly stoppered plastic bottle.
29. STANDARD SILICA SOLUTION:-Dilute 10 ml. stock solution to 1 lit. with recently boiled & cooled water this solution contains 10 mg/lit. Sio2 or 1 ml. =10 Sio2. Store in a tightly stoppered plastic bottle.
30. AMMONIUM MOLYBDATE SOLUTION FOR PHOSPHATE ESTIMATION:-Dissolve 25 gms. of ammonium molybdate in 175 ml. of distilled water. In another container add, cautiously to 400 ml. of distilled water, 310 ml. of conc. H2SO4. Cool it & add the molybdate solution to this distilled acid & dilute the whole to 1 lit.
31. STANNOUS CHLORIDE SOLUTION:-Dissolve 2.5 gms. of fresh supply of stannous chloride (SnCl2,2H2O) in 10 ml. of conc. Hcl & dilute to 100 ml. with distilled or deionised water. Filter if it is turbid. Store the solution in a cool place in a aspirator bottle having class stopcock. A 5 mm. thick layer of pure mineral oil shall be floated over the surface of the solution to minimise oxidation. Always drain out a little of solution out of the stopcock before use.
32. STANDARD PHOSPHATE SOLUTION:-Dissolve 0.716 g of dry potassium dihydrogen phosphate (KH2PO4) in 1 lit. of distilled water. Dilute 100 ml. of solution to 1lit. 1ml. of this solution =0.05 mg of phosphate (as PO4 ).
33. STANDARD 0.1 N POTASSIUM PERMANGANATE SOLUTION:-Dissolve 3.1608 g of potassium permanganate (dried at 105 deg C ) in distilled water made upto 1 lit. This solution must be stored in the dark.
34. STANDARD 0.1 N OXALIC ACID SOLUTION:-Dissolve 4.5018 g of oxalic acid in distilled water, make upto 1lit.
35. PHOSPHATE BUFFER SOLUTION O.5 M (FOR FREE CHLORINE):-Dissolve 22.68 g Na2HPO4 & 46.19 g KH2PO4 (both dried overnight at 105 deg C) & dilute to 1 lit. with distilled water. Let this solution age for No. of days & filter if any precipitate appears.
36. PHOSPHATE BUFFER SOLUTION 0.1 M:-Dilute 200 ml. of 0.5 M filtered phosphate buffer solution to 1 lit.
37. STOCK CHROMATE- DICHROMATE SOLUTION:-Dissolve 1.55 g K2Cr2O7 & 4.65 g K2CrO4 in 0.1 M phosphate buffer solution.
38. DILUTE CHROMATE DICHROMATE SOLUTION:-Dilute 100 ml. stock solution to 1 lit. with 0.1 M phosphate buffer solution. On dilution of 1ml. of this solution to 100 ml. with 0.1 M phosphate buffer solution gives a very close visual match with the yellow colour produced by 0.01 mg/lit. residual chlorine.
39. O-TOLUDINE REAGENT:-Dissolve 1.35 g of O-toludine dihydrogen chloride in 500 ml. distilled water & add with constant stirring to a solution of 150 ml. conc. Hcl in 350 ml. distilled water.
40. SODIUM ARSENITE SOLUTION:-Dissolve 5 g of sodium meta arsenite in 1lit. distilled water.
41. PHENOLPHTHALEIN INDICATOR SOLUTION:-Dissolve 0.1 g of phenolphthalein in 60 ml. of rectified spirit & dilute with distilled water to 100 ml.
42. METHYL ORANGE INDICATOR SOLUTION:-Dissolve 50 mg. methyl orange powder in distilled water & dilute to 100 ml.

43. SCREENED METHYL ORANGE INDICATOR SOLUTION:-Dissolve 0.2 g crystalline methyl orange in a mixture of 25 ml. of methylated spirit & 25 ml. of deionised water. Dissolve 0.28 g xylene cyanol FF in a mixture of 25 ml. of methylated spirit & 25 ml. deionised water. Mix the two solutions together.
44. 5% POTASSIUM DICHROMATE INDICATOR SOLUTION:-Dissolve 50 g K2CrO4 in little distilled water. Add Silver Nitrate solution until a definite red precipitate is formed. Let it stand for 12 hr. filter & dilute to 1 lit with distilled water.
45. SODIUM THIOSULPHATE 0.1 N SOLUTION:-Dissolve 25 gm Na2S2O3,5H2O & dilute to 1 lit. with distilled water.
46. DIPHENYL CARBAZONE INDICATOR SOLUTION:-Dissolve 0.4 g of di phenyl carbazone in 100 ml. of 95% is propanol
47. 4 M NICKEL NITRATE SOLUTION.:-Dissolve 1163 gms. of nickel nitrate (Ni(NO3)2,6H2O)in 1 lit. of D.M. water.
48. ERIOCHROME BLACK T INDICATOR SOLUTION:-Mix 0.5 g of sodium salts of Eriochrome Black T ( 1- hydroxy-2-naphthylazo)-5-nitro-2-naphthol-4-sulphonic acid) with 4.5 gms hydroxylamine hydrochloride. Dissolve this mixture in 100 ml. of 95% ethyl or isopropyl alcohol.
a) Mix together 0.5 g dye & 100 g NaCl to prepare a dry powder mixture.
49. MUREXIDE INDICATOR SOLUTION
a) Dissolve 150 g of Murexide (ammonium purpurate) in 100 g of absolute ethylene glycol. Water solution of the dye is not stable for longer than a day.
b) Mix 200 mg. of murexide with 100 gms. of solid NaCl & grinding the mixture to 40 to 50 mesh.
c) Titrate immediately after adding the indicator because it is unstable under alkaline conditions.
50. STARCH INDICATOR SOLUTION:-Dissolve 5 gms of starch & 0.01 gms of mercuric iodide with 30 ml. of cold distilled water & slowly pour it with constant stirring into 1 lit. of boiling distilled water. Boil for 3 min & allow it to cool then decant off the supernatant clear liquid.
51. HYDROXYLAMINE HYDROCHLORIDE SOLUTION FOR Fe :-Dissolve 10 gms. NH2OH & HCl in 100 ml. distilled water.

Water analysis

TURBIDITY
The sample is matched against standard suspensions of fuller’s earth in water.
TERMINOLOGY
For the purpose of this test, the following definition shall apply. Scale Unit - Turbidity imparted by 1 mg of fullers earth when suspended in 1000 ml of distilled water.
PREPARATION OF TURBIDITY STANDARDS
Mix slowly with constant stirring 5.000 g of fullers earth previously dried and shifted through 75 micron IS Sieve with distilled water and dilute it to 1000 ml. Agitate intermittently for one hour and then allow to stand for 24 hours. Withdraw the supernatant liquid without disturbing the sediment. Vaporate about 50 ml of the removed liquid, dry the residue at 105 + 2 Deg. C and weigh the residue to determine the amount of clay in suspension. Prepare turbidity standards with this standardised stock suspension with distilled water. A drop of saturated mercuric chloride solution may be added as preservative. The standards are stable for three months.
PROCEDURE
Pour the sample after thorough shaking into a clear glass bottle of suitable capacity, say, one litre. Compare it with the turbidity standards contained in similar bottles, holding them against a suitable background and using a source of light which illuminates them equally and is placed so that no rays reach the eye directly. The sample and the standards shall be shaken simultaneously immediately before comparison. If the sample has turbidity over 100 units, dilute it with distilled water before testing and multiply the result with an appropriate factor.
NOTE: Comparison of turbidity may also be done with the help of suitable instruments.


COLOUR
The colour of the sample is matched against a series of standards containing potassium chloroplatinate and cobalt chloride.
TERMINOLOGY
For the purpose of this test, the following definitions shall apply :
True Colour
Colour due to substances in solution, after removal of suspended matter.
Apparent Colour
Colour due to substances which are in solution as well as in suspension.
Hazen Unit
Colour obtained in a mixture containing either on milligram of Patinum or 2.49 mg of potassium chloroplatinate along with 2 mg of cobalt chloride (CoCl2.6H2O) in 1 litre of the solution.
APPARATUS

Nessler Tubes - Flat-bottom tube of thin colourless glass. Two types of tubes are required. The longer tubes shall be 45 cm tall and 2.5 cm in internal diameter. The shorter tubes shall be 30 cm tall and 1.7 cm in internal diameter. Tubes of any one type shall be identical in shape, and the depth measured internally from the graduation mark to the bottom shall not vary by more than 2 mm in the tubes used.
REAGENTS
Platinum or Potassium Chloroplatinate Aqua Regia - prepared by mixing one part by volume of concentrated nitric acid (conforming to IS:264-1950) with three parts by volume of concentrated hydrochloric acid (conforming to IS:265-1962). Cobalt Chloride-Crystalline, with the molecular composition CoCl2.6H2).
PROCEDURE
(1) PREPARATION OF COLOUR STANDARDS

Dissolve 0.500 g of metallic platinum in aqua regia and remove nitric acid by repeated evaporation to dryness on water bath after addition of excess of concentrated hydrochloric acid (conforming to IS:265-1962). Dissolve the residue with 1.0 g of cobalt chloride in 100 ml of concentrated hydrochloric acid to obtain a bright solution, if necessary by warming. Dilute the solution to 1000 ml with distilled water. This stock solution has a colour of 500 Hazen units. A more convenient way of preparing the same solution is by dissolving 1.245 g of potassium chloroplatinate and 1.0 g of cobalt chloride in distilled water and diluting to 1 litre. Prepare a set of colour standards having colour 5, 10, 15, 20, 25, 30, 35, 40, 50, 60 and 70 Hazen units by diluting the stock solution with water. Protect these colour standards from evaporation and contamination when not in use. The colour standards shall be freshly prepared for each determination. But in routine practice, they may be used repeatedly, provided they are protected against evaporation and contamination when not in use.


(2) PROCEDURE FOR CLEAR SAMPLES
For samples having turbidity under 5 mg/l, match the colour of the sample against the standard colours in the longer Nessler Tubes. Fill the tubes to mark and compare the colour by looking vertically downwards against a pure white surface. If the colour is found to exceed 70 units, dilute the sample with distilled water before comparison and multiply the result by appropriate factor. As matching is very difficult when the colour of the sample is below 5 Hazen units, report the colour as less than 5 Hazen units in such cases. When the colour of the sample exceeds 30 Hazen units, the comparison may, if desired, be made in the shorter Nessler tubes.


(3) PROCEDURE FOR TURBID SAMPLES
If the sample has turbidity over 5 mg/l it becomes impossible to measure the true colour accurately by the method prescribed in PROCEDURE for clear samples and if an attempt is made, the value found shall be reported as "apparent colour". In the presence of turbidity, the true colour shall be determined after centrifuging. The sample shall be centrifuged until the supernate liquid is clear. The centrifuged clear sample shall be compared by the method prescribed in PROCEDURE for clear samples.
NOTE: For estimating true colour, filter paper shall not be used since that leads to erroneous results.
REPORT
The results of colour determination shall be excess in whole numbers and shall be recorded as follows :
Hazen Units
Less than 5 Report as "Less than 5 Hazen Units"
5 to 50 Report to the nearest 1 Hazen Unit
51 to 100 Report to the nearest 5 Hazen Unit
101 to 250 Report to the nearest 10 Hazen Unit
251 to 500 Report to the nearest 20 Hazen Unit
NOTE: The colour determination shall be made as early as possible after the collection of samples as certain biological change occurring in storage may affect the colour.

ELECTRICAL CONDUCTANCE
The unit of conductance is the mho or reciprocal ohm. Specific conductivity is the conductance at a specified temperature across a column of a liquid 1 cm2 in area and 1 cm long, and is expressed mhos per centimetre. This is an inconveniently large unit for water testing and it is usual to use the micromhos per centimetre known as the "dionic unit", which is one-millionth part of a mho per centimetre.
APPARATUS
Several kinds of apparatus are available. They generally consist of two parts.
CONDUCTIVITY CELL
Containing a pair of electrodes. The sample to be tested is poured into this cell. There are many forms of cell. One of the most convenient types is provided with a funnel for filling, a drain for emptying, and an overflow for maintaining constant level. Electrodes for use with samples having very low dissolved solids (such as condensates) should not be coated with platinum black. Platinum black which has been heated to redness until it is grey is suitable. Bright platinum or gold or heavily gold plated electrodes may be used. Some instruments are designed to work with particular form of conductivity cell, and are then calibrated directly in conductivity units. Other instruments, primarily introduced for more general application, are calibrated on conductance units and their readings require multiplication by a factor known as the "cell-constant" which shall be determined by experiment. Measuring Instrument - For measuring the electrical conductance (or the resistance which is the inverse of conductance) between the electrodes of the cell. There are several satisfactory commercial models. Operators, less they have adequate facilities, would be well advised to purchase a ready made instrument.
PROCEDURE
Determine the cell constant if necessary, either directly with a standard potassium chloride solution (say 0.002 N) or by comparison with a cell the constant of which is known accurately. (In the latter case, the concentration and nature of the electrolytes in the liquid which is used for the comparison should be the same and should be similar respectively to those of the liquids with which the cell is likely to be used in practice). Use some of the samples to wash out the conductivity cell thoroughly. Fill the conductivity cell with the sample. Measure the conductivity in accordance with the instructions of the instrument manufacturer.
Calculations
FOR INSTRUMENT READING RESISTANCE :
Electrical conductance, in dionic units
(or micromhos per centimetre) = 1 x 10 6
rk
Where r = Resistance in ohms, and k = Cell constant
FOR INSTRUMENT READING CONDUCTANCE :
Electrical conductance, in dionic units
(or micromhos per centimetre) = ck
Where c = conductance in micromhos, and k = cell constant


TOTAL DISSOLVED SOLIDS
A well mixed filtered sample is evaporated in a weighed dish and dried to constant weight in an oven at 103 to 105 Deg. C. The increase in weight over that of the empty dish represents the total residue.
APPARATUS
1. Silica or porcelain dish of 100 ml capacity
2. Desicator
3. Oven
PROCEDURE
Ignite the clean evaporating dish at 550 + 50 Deg. C for 1 hour. Cool, desiccate and weigh. Transfer the measured sample to the preweighed dish and evaporate to dryness on a steam bath. Choose a sample volume that will yield a minimum residue of 25 mg to 250 mg. If necessary, add successive portions of sample to the same dish. Dry the evaporated sample for atleast 1 hour at 103 to 105 Deg. C. Cool the dish in a desiccator and weigh. Repeat the cycle of drying, cooling and weighing until a constant weight is obtained.
Calculations
Total dissolved solids, mg/litr = wt of residue x 1000
ml. of sample taken


CORRELATION OF ELECTRICAL CONDUCTANCE TO TOTAL DISSOLVED SOLIDS

For water containing a given mixture of mineral salts, the electrical conductance is closely proportional to the dissolved solids. When the samples are known to be free from wide fluctuation in mineral content, the electrical conductance offers a quick means of computing the total dissolved solids. However, this PROCEDURE may be used only after ascertaining the appropriate conversion factor for a particular series of samples.


SUSPENDED MATTERS
Suspended matter is the material retained on filter after filtration of a well mixed sample of water. The residue is dried at 103 to 105 Deg. C.
APPARATUS
1. Gooch crucible
2. Silica or porcelain evaporating dish of 100 ml capacity
3. Desiccator
4. Oven adjustable to constant temp of 103 - 105 Deg. C.
5. Water batch
PROCEDURE
Prepare a gooch crucible with asbestos (20 to 30 ml of 0.5% suspension of gooch asbestos added and washed under suction), dry and ignite at 500 Deg. C for atleast 30 minutes, cool and weigh. Filter a suitable volume of the well mixed sample through the crucible. Wash with distilled water, dry at 105 Deg. C for one hour. Weigh.
Calculations
Suspended matter, mg/lit = w x 106
V
Where,
w = wt. in g of the suspended matter
V = vol. in ml. of the sample taken for filteration
NOTE: If Gooch Crucible is not available, standard "Whatman" filter paper may be used.



EQUIVALENT MINERAL ACIDITY
All the chlorides, sulfates, nitrates of Ca, Mg, Na. etc. are converted to corresponding mineral acids when they come into contact with strongly acidic cation exchanger like Tulsion-42. When the Performance of the cation unit is satisfactory the EMA and free mineral acidity (FMA) will be one and the same. Therefore, to have thorough control over the cation unit, EMA test is necessary.
PRINCIPLE
Some quantity of the water is allowed to pass through a cation exchanger Tulsion - 42 in hydrogen form, the effluent is collected and titrated against standard alkali and EMA is expressed as CaCO3.
Ca } Cl Ca } Cl

R.H. + Mg } SO4 ----- R. Mg + H } SO4

Na } HCO3 Na } HCO3

REAGENTS
1. Strongly acidic cation exchanger Tulsion - 42 in H+ form.
2. 2 NHCl
3. Standard 0.02 N sodium hydroxide solution
PROCEDURE
A. REGENERATION OF RESIN COLUMN
1. Fill up the column with about 50 ml. of cation resin uniformly and soak it in DM water. Remove any air bubbles.
2. Regenerate with 200 ml of 2 N HCl at the rate of 5 ml/min.
3. Rinse it thoroughly with distilled water till the effluent becomes neutral.
4. Always keep some amount of distilled water over the column.
B. DETERMINATION
1. Add the water to be tested slowly and pass through the column at the rate of 5 ml/min.
2. Discard the first 50 ml portion of the effluent and collect the rest in flask.
3. Pipette out 50 ml from it and add 2 drops of mixed indicator. Titrate against standard 0.02 N NaOH.
Calculations
EMA, as CaCO3, mg/lit = ml. of titrant x 1000
ml of sample



ACIDITY
The acidity of a water may be caused by the presence of uncombined (free) carbon dioxide mineral acids and salts of strong acids and weak bases. The test is based on the titration of a sample with a standard solution of a strong base. Titration to the methyl orange end point (pH 4.5) is arbitrarily defined as "free acidity". It measures the relatively strong acids such as mineral acids. Titration to phenolphthalein end point pH 8.3 is defined as "total acidity" and it includes also the weak acids, acid salts, and some acidity due to hydrolysis.
REAGENTS
1. 0.02 N Sodium hydroxide.
2. Phenolphthalein indicator solution
3. Methyl orange indicator solution.
PROCEDURE
a) Phenolphthalein acidity (total acidity).
Take 50 ml or 100 ml of sample in an Erlenmeyer flask, add 0.15 to 0.5 ml (3 to 10 drops) of phenolphthalein indicator and titrate with standard 0.02 N NaOH to the same colour as that of the pH 8.3 NaHCO3, colour standard.
Calculations
mg/lit of phenolphthalein ml of 0.02 N.NaOH x 1000
or total acidity as CaCO3 = ml of sample
b) Methyl Orange or Mineral Acidity.
Take 50 or 100 ml of sample in an Erlenmeyer flask. Add 2 drops of methyl orange indicator to the sample and titrate with standard 0.02 N.NaOH to the very faint orange colour characteristic to pH 4.5.
Calculations
mg/lit of methyl orange or ml of 0.02 N.NaOH x 1000
mineral acidity as CaCO3 = ml of sample

NOTE:- If residual chlorine is present it is removed by addition of small amount (0.05 to 0.1 ml) of 0.1 N.Na2S2O3 to avoid interference with methyl orange colour change.


ALKALINITY
The alkalinity of a natural water is mainly due to the presence of carbonates, bicarbonates and hydroxides, and less frequently to borates, silicates and phosphates. Alkalinity is determined by titration with a standard solution of strong acid to certain end points as given by indicator solutions. Phenolphthalein contributed by hydroxide and carbonate and methyl orange or screened methyl orange is used for the second point (approximately pH 4-5) contributed by the bicarbonates.
REAGENTS
1. 0.02 N sulphuric acid.
2. Phenolphthalein indicator solution
3. Methyl orange indicator or SMO solution
PROCEDURE
a) Phenolphthalein alkalinity
Take 50 ml or 100 ml of sample in an Erlenmeyer flask, add 2 drops of phenolphthalein indicator, and titrate over a white surface with 0.02 N H2SO4 until the pink coloration just disappears.
Calculations:
mg/lit phenolphthalein ml of 0.02 N H2SO4 x 1000
alkalinity as CaCO3 = ml of sample
b) Total or methyl orange alkalinity
Take 50 ml or 100 ml of the sample. Add 2 drops of methyl orange indicator, and titrate with 0.02 N H2SO4 until the colour changes from yellow to faint orange.
Calculations :
mg/lit total or methyl ml of 0.02 N H2SO4 x 1000
orange alk. as CaCO3 = ml of sample


calculations of Hydroxide, Carbonate, Bicarbonate and total Alkalinity :
The different types of alkalinities are determined by using separately phenolphthalein and methyl orange as indicator for titration. The relative quantities of bicarbonate, carbonate, hydroxide and total alkalinity can be obtained from the following table :
Value of P & M Alkalinity Bicarbonate Alkalinity Carbonate Alkalinity Hydroxide Alkalinity Total Alkalinity
Value of P & M Bicarbonate Carbonate Hydroxide Total

Alkalinity Alkalinity Alkalinity Alkalinity Alkalinity
P = zero M Nil Nil M
P <>
P = 1/2 M Nil 2P Nil M

P > 1/2 M Nil 2(M-P) 2P - M M

P = M Nil Nil P M

NOTE
1. If water is prechlorinated, add 2 drops of 0.1 N sodium thiosulphate solution, before addition of methyl orange indicator.
2. In the presence of alkali phosphates :
3. In the presence of phosphate treatment and where the phosphate is present as a trisodium salt, part of the alkalinity to phenolphthalein will be due to the alkalinity combined with the phosphate (PO4). If the phosphate content (as PO4) is expressed as mg/l; the effect on P will be equal to one half of the content in mg/l of phosphate and this shall be subtracted from P reading before using the above table. The alkalinity to phenolphthalein after addition of BaCl2 is not affected by the presence of phosphate.
PROCEDURE

To 100 ml of sample add a crystal of sodium sulphate and 10 of 10% BaCl2 solution. Mix well for 2 minutes and titrate using phenolphthalein as indicator.
Calculations
mg/lit of P (BaCl2) Value = ml of 0.02 N H2SO4 x 1000
ml of sample



FREE CARBON DIOXIDE
Free carbon dioxide is the term used to designate carbon dioxide gas dissolved in water. The designation "free" carbon dioxide is used to differentiate a solution of carbon dioxide gas from combined carbon dioxide present in the form of bicarbonate and carbonate ions. The CO2 content often is the sole contributor to the acidity of the sample.
REAGENTS
1. Standard 0.02 N NaOH solution
2. Phenolphthalein indicator solution
PROCEDURE
Collect the water sample in a glass bottle by allowing the water to flow from the bottom through a rubber tube connected to the source. Allow the water to overflow 2 to 3 times the capacity of the bottle and close. In the laboratory syphon the sample into 100 ml graduated cylinder and allow some over flow to take place. Quickly adjust the sample volume to 100 ml and add 0.25 - 0.5 ml (5 to 10 drops) phenolphthalein indicator. If the sample remains colourless titrate rapidly with standard NaOH to the colour of pH 8.3 NaHCO3 colour standard resting along side in an identical graduated cylinder. Repeat the determination on a second sample by adding full alkali volume of the first titration and if the sample remains colourless complete the titration. Accept the second titration as the more reliable results.
Calculations
CO2 as CO2, mg/lit = Titrant x N of NaOH x 1000 x 44
ml of sample

RESIDUAL CARBON DIOXIDE IN CATION EXCHANGER TREATED WATER :-
Residual carbon dioxide is normally checked in cation exchanger treated water or degasser outlet to check total anionic load on anion exchanger.
REAGENTS
1. 0.02 N standard sodium hydroxide solution
2. Phenolphthalein indicator solution
3. Methyl orange indicator solution
PROCEDURE
Collect the sample by means of rubber tubing discharging at the bottom of a graduated cylinder or nessler tube. Allow the sample to overflow for a few minutes and withdraw the tubing while the sample is flowing. Flick the cylinder to throw off excess sample above the 100 ml mark. To this 100 ml add methyl orange indicator and titrate against standard sodium hydroxide. To the second sample add enolphthalein indicator, and titrate against standard sodium hydroxide.
Calculations
Residual carbon dioxide in
decationized water mg. CO2/lit = (B-A) x 1000 x 0.88
100
Where B = ml of standard sodium hydroxide required for phenolphthalein end point
A = ml of standard sodium hydroxide required methyl orange end point
NOTE
1. The standard sodium hydroxide is rendered carbonate free by passing the solution through a strongly basic anion exchanger, Tulsion A-27 in the OH form.
2. Where the free carbon dioxide content of the water sample is high, some loss of CO2 occurs.

SODIUM BY FLAME PHOTOMETRY
Flame Photometry is concerned with the emission of characteristic radiation in flames by individual elements and the co-relation of the emission intensity with the concentration of the elements. A small volume of the solution of the sample is placed in a cup of an atomiser. Air or oxygen and a combustible gas are fed to the atomiser at controlled rates of flow and the solution is vaporised in a special burner. At the high temperature of the flame, the salts vaporise and dissociate into the constituent atoms or radicals. The vapours of the metal atoms are then excited atoms radiate their characteristic special line, the intensity of which is a relative measure of the metal in solution. This intensity is measured by suitable instruments.
REAGENTS
1.Standard Sodium Solutions for Calibration Curves :-
Dissolve 2.5418 g of A.R. sodium chloride in 1 lit of distilled water in a volumetric flask. This solution contains the equivalent of 1.0 mg Na per ml. Dilute this stock solution to give four solutions containing 10, 5, 3 and 1 ppm sodium ions.
2.Standard Potassium Solution for Calibration Curves :-Dissolve 1.9090 g of A.R. potassium chloride in 1 lit of distilled water in a volumetric flask. This solution contains the equivalent of 1.0 mg/ per ml. Dilute this stock solution to give four solutions containing 10, 5, 3 and 1 ppm potassium ions.
PROCEDURE
The operating manual supplied with the instruments should be read before attempting any work. A general approach is described :
1. Adjust the sensitivity control to the minimum value.
2. Turn the gas supply and light the gas at the burner.
3. Adjust the air supply till a blue flame is obtained.
4. Charge the small sample beaker with distilled water and place it in position.
5. Fine adjustment of air supply so that the blue cone of the flame just forms ten separate cones, one to each burner hole.
6. Place the appropriate filter in position.
7. Spray standard solution containing the ion to be determined and by means of the calibrated potentiometer, adjust the galvanometer to read approximately full scale deflection.
8. Spray distilled water and adjust the galvanometer spot to read zero by means of the zero control.
9. Spray standard solution again and readjust the sensitivity control for full scale deflection of the galvanometer.
10. Check the zero by spraying with distilled water.
11. Spray solutions of known concentration but less than that of the standard solution, and note the galvanometer reading at each concentration. Plot the galvanometer reading against the concentration, expressed say as ppm and thus prepare a calibration curve for each element.
12. Spray the unknown solution in the flame. Note the galvanometer deflection and evaluate the concentration from the calibration curve.
NOTE: If it is known that the solution contains a sufficient concentration of an interfering substance to affect the reading it will be necessary to employ standard solutions which also contain approximately the same concentration of the interfering substance as is present in the sample. The ideal method of removing interferences is to separate the element being determined by chemical means, but this procedure is not always practicable.

HARDNESS
Hardness in water is due to the presence of bicarbonates, chlorides and sulphates of calcium and magnesium. Temporary hardness is due to the presence of bicarbonates and permanent hardness due to the presence of chlorides and sulphates. Sometimes, hardness may include iron, aluminium, zinc, manganese, etc.
COMPLEXAMETRIC METHOD (EDTA METHOD A)
EDTA forms a chelated soluble complex when added to a solution of certain metal ions. If a small amount of EBT is added to an aqueous solution containing calcium and magnesium ions at pH of 10.0 + 0.1, the solution will become red wine. If EDTA is then added as a titrant, the calcium and magnesium will be complexed. After sufficient EDTA has been added to complex all the calcium and magnesium, the solution will turn blue from red wine.
REAGENTS
1. Ammonia buffer of pH 10.
2. M solution of disodium salt of ethylenediamine tetra acetic acid.
3. Eriochrome black T indicator solution.
PROCEDURE
Take 50 ml of sample in an Erlenmeyer flask, add 4 to 6 drops of Eriochrome black T indicator solution. Add 1 ml of buffer solution and mix. Titrate immediately with EDTA solution till the colour changes from red to blue.
Calculations:
Total hardness as CaCO3 mg/lit = Vol. of 0.01 M EDTA soln. x 1000
ml of sample
NOTE: For checking hardness in soft water use 500 ml of the sample into 750 ml evaporating dish and add 3 ml of buffer solution followed by 10-12 drops of indicator solution.
SOAP SOLUTION FOR HARDNESS TESTING (METHOD B)
This is a quick method for checking hardness of treated water or an accurate determination of the hardness of treated water, EDTA method for hardness should be used.
REAGENTS
1. “B” soap solution
2. 40 ml shaking bottle
PROCEDURE
Take water sample upto 40 ml mark in shaking bottle. Add 10 drops of the "B" soap solution. Shake vigorously. If a lather is obtained which will last for 1 to 2 minutes, the water is soft. If no lather is obtained, or if the lather does not last, the water is hard.
NOTE
1. Rinse the shaking bottle clean with soft water thoroughly.
2. The soap solution bottle should be kept tightly stoppered. It will otherwise evaporate and give false reading.

CALCIUM HARDNESS
The water sample is titrated against EDTA solution using Murexide indicator (ammonium purpurate) in highly alkaline medium.
REAGENTS
1. Approximately 1 N sodium hydroxide solution
2. 0.01 M standard EDTA solution
3. Murexide indicator
PROCEDURE
Prepare a colour comparison blank in a white porcelain basin by stirring 2.0 ml of 1 N. NaOH, 0.2 g solid indicator mixture (or 4 to 6 drops of indicator solution) into 50 ml of distilled water and sufficient EDTA titrant (0.05 to 0.1 ml) to produce an unchaning purple colour. Pipette into a similar basin 50 ml. of sample, neutralize the alkalinity with 0.02 N. HCl, boil for 2 to 3 minutes to expel the CO2 and cool to room temperature. Add 2.0 ml 1 N NaOH, or a volume sufficient to produce a pH of 12 to 13 and mix. Add 0.2 g of powdered indicator. Stirring constantly titrate with standard EDTA solution to the colour of comparison blank. Check the end point by adding 1 or 2 drops of titrant in excess to be sure that no further deepening of the purple colour takes place.
Calculations
Calcium, as CaCO3, mg/lit = (A-B) x C x 1000
ml of sample
Where A = ml of EDTA required for titration of sample
B = ml of EDTA required for blank
C = mg of CaCO3 equivalent to 1.0 ml of EDTA
NOTE: The only serious interference with the EDTA titrant of calcium is that of orthophosphate ion. If the calcium hardness exceeds about 60 ppm CaCO3, and the concentration of orthophosphate is 10 ppm, or more, calcium phosphate is precipitated when the pH is raised to 12, giving low results. Phosphate, if present, can be removed by ion exchange.


IRON

Iron is frequently found in natural waters. In addition to the "natural" iron content of a water, iron is passed into solution when the corrosion of iron and steel surface occur.
O-PHENANHROLINE METHOD (METHOD A)
The calorimetric estimation of iron is based on the formation of the orange red phenanthroline complex (C12 H2 N2)3 Fe++ in the pH range 2-9. Below pH 2 the colour develops slowly and is much weaker. Since this complex is formed with ferrous iron Hydroxylamine, hydrochloride is the most satisfactory reducing agent (for the reduction of ferric iron). Certain divalent metals such as Cd, Hg and Zn form slightly soluble complexes with the reagent and reduce the intensity of the iron colour, but, this interference may be minimised by adding a large excess of reagent. Phosphorous may be present upto 20 ppm. Fluoride (500 ppm) does not interfere if the pH is kept above 4.0.
REAGENTS
1. Standard iron solution
2. 1-10 phenanthroline monohydrate REAGENTS
3. Ammonium acetate buffer solution
4. Hydroxylamine hydrochloride
PROCEDURE
For total iron use well mixed sample. For determination of dissolved iron if precipitated iron is present, decant a sample allow to settle down the precipitations and filter. If precipitated iron is present, use the filtrate. Prepare a series of visual standards/photometric calibration curve by measuring the following amounts of standard iron solutions into beakers, 0.01, 0.02, 0.03, 0.04, 0.05 upto 0.1 mg. Dilute the solution to 50 ml. To the sample, blank and the standards add 2 ml conc. HCl, 1 ml hydroxylamine solution, glass beads and boil until the volume is reduce to 15 to 20 ml. Transfer the solution to Nessler tubes if visual comparison is to be made or to 50 or 100 ml volumetric flasks if spectrophotometric method is used. Add 10 ml ammonium acetate buffer and 5 ml 1-10 phenanthroline reagent, dilute to the mark with distilled water, and mix well. After 10 to 15 minutes compare the colour visually or measure the absorbance at 510 mm. The colour forms in the range of pH 2-9 and is very stable.
Calculation
Iron as Fe, mg/lit = mg of Fe x 1000
ml of sample
IRON BY THIOGLYCOLLIC ACID METHOD (METHOD B)
In ammoniacal medium, mercaptoacetate (as the ammonium salt HSCH2 COONH4) reacts with iron to yield the soluble red purple product Fe (OH) (SCH2COO)2 containing iron in the ferric state. Ferrous iron reacts to give the same complex by air oxidation. In the absence of oxygen, the colour slowly fades as a result of the reduction of ferric iron to ferrous and oxidation of mercaptoacetate to the disulphide - O2 CCH2 SSCH2CO2. The air oxidation of ferrous iron in the system is very rapid and usually under analytical conditions, more than the pace of the reduction so that a stable coloration is obtained. The reaction must be carried out in basic medium, precipitation of metal hydroxides may be prevented by adding citrate. Certain metals among them Cu (21 mg), Arsenic +3 (> 100 mg), Tin+2, Zinc (> 10 mg) and cadmium black, the iron colour, although this effect can be diminished by the addition of more reagent. Very high concentration of salts of alkali metals decrease the colour intensity somewhat. On the other hand anions have but a slight effect on the colour. As much as 5000 ppm chloride, fluoride, orthophosphate, tartrate, oxalate and citrate do not interfere. The colour is fairly stable (atleast 6 hours in diffuse light).
REAGENTS
1. Thioglycolic acid (80%)
2. Ammonia solution (sp. gr. 0.91)
PROCEDURE
Take 100 ml of water sample into a 250 ml beaker. Add 2.5 ml of thioglycollic acid reagent. After stirring evaporate in sand or water bath to 5 ml (not less), then allow to cool. Add 5.0 ml of ammonia solution, shake and pour into the 25 ml measuring flask. Make upto the mark. Measure optical density at 540 mm using 5 cms cell. Reagent blank and standard to be carried simultaneously.
Calculations
Iron as Fe, mg./lit = mg. of Fe x 1000
ml. of sample



SILICA
The silica content of natural water will vary to a considerable extent depending on the locality. The presence of silica is particularly objectionable in water used for boiler feed purpose as it may lead to the formation of hard dense scale. In addition, a very serious problem encountered in high pressure operations is the deposition of siliceous materials on turbine blades & super heaters. The gravimetric method is the standard applicable above 20 mg / lit SiO2 content . This method should be followed for standardisation of standard silicate solution used in colometric methods. The heteropoly blue colometric method is adaptable for the range of 0 to 2 mg / lit SiO2 & yellow molyb silicate method in the range of 0 to 20 mg / lit . Reagent blank should always be used in all the three methods.
GRAVIMETRIC METHOD (METHOD A)
Take a sample to contain atleast 10 mg of SiO2 . If necessary clarify by filtration. Acidify with 2 or 3 ml of conc. Hcl & evaporate to dryness in a platinum dish on a water bath . At regular intervals add 2 or more portions of 2 to 3 ml of conc. HCl as additional quantities of sample is added to the dish. Bake the evaporated residue in an oven ad 110 Deg. C for about an hour. Add 5 ml. of conc. Hcl warm & add 50 ml distilled water. Loosen the clinging residue from the sides & the bottom of the dish & filter collecting the filtrate. Wash the dish & residue with hot 1 : 50 HCl & finally with distilled water until the washings are free from chloride. Return the filterate & washings to the platinum dish & again evaporate to dryness. Repeat as previously, collecting the residue in another filter paper. Dry the two filter papers with residue ,burn, ignite at 1000-1200 Deg C in a platinum crucible & weigh . Moisten the residue with a few drops of distilled water , add 2 drops of H2SO4 & 10 ml. 48% HF . Cautiously evaporate to dryness on a steam bath in a fume cupboard . Again ignite at 1000-1200 Deg. C. Cool & weigh. Carry out a blank.
Calculations
( A - B ) - ( C - D ) x 1000
SiO2, as SIO2 mg / lit = ml of sample
Where A = Weight of crucible & sample residue in mg. after first ignition
B = Weight of crucible & sample residue in mg. after HF treatment & second ignition.
C = Weight of crucible & blank residue in mg. after first ignition
D = Weight of crucible & blank residue in mg. after HF treatment & second ignition.
COLOMETRIC ESTIMATION OF SILICA (REACTIVE SILICA METHOD B )
Ammonium molybdate at approximately pH 1.2 reacts with silica & any phosphate present to produce hteropoly acids. Oxalic acid is added to destroy the molybdophosphoric acid but not the molybdosilicic acid . Even if phosphate is known to be absent , the addition of oxalic acid is highly desirable & is a mandatory step . The intensity of the yellow colour is proportional to the concentration of molybdate- reactive silica. The yellow molybdosilicic acid is reduced by means of 1 amino - 2- naphthol - 4 - sulphonic acid to heteropoly- blue. The blue colour is more intense than the yellow colour & provides increased sensitivity. In atleast one of its forms , silica does not react with molybdate even though it is capable of passing through filter paper & is not noticeable turbid. The presence of such a molybdate unreactive silica is undesirable in raw water .It will not be removed in the water treatment plant & will find its way to highly pressure stream system , where it will be converted to " molybdate-reactive " silica. Such increase in silica content will give rise to scale problem .
Chromate & large amounts of fe, PO4, sulphide, tannin, colour & turbidity are potential interferences. Oxalic acid treatment suppresses PO4 & reduces tannin interference. Inorganic sulphide can be removed by boiling an acidified sample. The addition of 1 ml. of 1% EDTA solution after molybdate reagent overcomes high Fe & Ca concentrations.
COLOMETRIC ESTIMATION OF SILICA :- (0- 20 PPM SiO2)
REAGENTS
1. Ammonium molybdate solution
2. 2 N sulphuric acid.
3. 10 % oxalic acid.
4. Lovibond comparator with standard silica disc.
PROCEDURE
1. Fill one of the Nessler tubes to the 50 ml. mark with sample & place in the left hand compartment of Lovibond comparator.
2. Fill the other Nessler tube with 50 ml. of sample at 25 - 30 Deg. C . Add 2 ml. of acidified ammonium molybdate solution . Mix thoroughly, add 4 ml. of oxalic acid & again mix thoroughly. Place in the right hand compartment & allow to stand for 10 minutes.
3. Stand the comparator facing a uniform source of light, compare the colour of the sample in the disc. Rotate the disc until the colours are matched.
Calculations
SiO2 in mg / lit as SiO2 = Disc reading x 20
NOTES
1. Should the colour in the test solution be deeper than the deepest standard , a fresh test should be carried out using a smaller quantity of sample & diluting to 50 ml. with distilled water before adding the REAGENTS.
2. Silica free water :
3. Distilled water from an all - metal "Still " or water which has been passed successively through a mixed bed deionisation unit & strongly basic anion exchanger such as Tulsion A27MP unit regenerated with a regeneration level of 320 gm per litre NaOH has been found to be suitable. Prepare & store in a polyethylene bottle a large batch of water containing not more than 0.005 ppm SiO2 , determine the silica content of water by treating it as a sample . This water is used to prepare reagents & standards , & to dilute samples when necessary .

COLOMETRIC ESTIMATION OF SILICA:- (0-2 PPM SiO2)
REAGENTS
1. Acidified ammonium molybdate solution.
2. 10 % oxalic acid.
3. Amino - naphthol reducing agent.
4. Lovibond comparator with standard silica disc or spectrophotometer suitable for measurement at 815 microsiemens wave length .
PROCEDURE
1. Fill one of Nessler tubes to the 50 ml . mark with sample, & place in the left hand compartment of Lovibond comparator.
2. Fill the other Nessler tube with 50 ml. of sample, at 25 -30 Deg.C. Add 2 ml. of acidified ammonium molybdate solution . Mix thoroughly, stand for 5 minutes . Add 4 ml of oxalic acid & mix well . Then 2 ml. of reducing agent, mix well compared with that of a blank comprising the same water without reagents, using Lovibond comparator or read the absorbance using a spectrophotometer (wave length 815 microsiemens). Compute the silica content from the standard graph prepared from the standard silica solution.
DETERMINATION OF TOTAL SILICA (MOLYBDATE REACTIVE & UNREACTIVE SILICA )METHOD C
The molybdate unreactive silica is converted to the reactive form or state by digesting the sample with sodium bicarbonate.
REAGENTS
1. Sodium bicarbonate .
2. 1 N sulphuric acid.
3. Other reagents as per previous method.
PROCEDURE
Take 100 ml. of sample or lesser quantity (20 - 100 micrograms SiO2) but made upto 100 ml. distilled water in a platinum dish. add 200 mg. silica free sodium bicarbonate & digest on a stream bath for one hour . Cool & add slowly , with stirring , 2.5 ml. sulphuric acid ( 1 N ) . Do not interrupt the analysis but proceed at once with the remaining steps . Transfer quantitatively into a plastic container. For development of colour & Calculations refer the previous procedure.

SULPHITE
The determination of sulphite usually is made only on boiler water. Generally speaking, sulphite is not present in natural water. In boiler, feed water sodium sulphite is fed to remove dissolved oxygen .
REAGENTS
1. Hydrochloric acid 1 + 1
2. Starch Indicator Solution:-Dissolve 5 gms of starch & 0.01 gms. of mercuric iodide with 30 ml. cold distilled water & slowly pour it with constant stirring in to 1 lit. of boiling distilled water. Boil for 3 minutes. Allow to cool & decant off supernatant clear liquid .
3. Standard Potassium Iodate:- Iodine Solution :Weigh accurately 0.713 gms. of potassium iodate & dissolve in about 150 ml. of distilled water. Add 7 gms of potassium iodide & 0.5 gms. of sodium bicarbonate. When dissolved, dilute the solution to exactly 1 litre.
PROCEDURE
Place 10 ml. of 1 +1 HCl in a 250 ml. flask. Rapidly add 100 ml sample, submerging the pipette tip below the acid surface to minimise air exposure . After adding 1 ml. starch indicator solution titrate with standard iodate - iodide ( KIO3 ) solution ,to the first appearance of persistent blue colour. Determine the blank titration by taking 100 ml. distilled water .
Calculations
Sulphite as SO3 , mg / lit = ( A - B ) x 100
Where , A = ml of titrant for sample
B = ml of titrant for blank
STANDARD IODATE- IODIDE SOLUTION
Weigh accurately 0.713 g of potassium iodate & dissolve in about 150 ml of distilled water. Add 7 g of potassium iodide & 0.5 g of sodium bicarbonate when dissolved dilute the solution to exactly 1 lit.
GRAVEMETRIC METHOD (SULPHATE METHOD A)
The sulphate is precipitated as barium sulphate by the addition of barium chloride to a slightly acidified solution of the sample at the boiling temperature. The precipitate is ignited and the residue is weighed as barium sulphate. The presence of silica and other non-volatile suspended matter cause high results. Sulphites and iron should also be present.
REAGENTS
1. Hydrochloric Acid 1:1
2. Methyl Red Indicator solution
3. Barium Chloride solution
PROCEDURE
Take sample to contain approx. 50 mg sulphate. Dilute to 250 ml. Adjust the acidity with HCL to Ph 4.5 to 5.0, using methyl red indicator . Then add an additional 1 to 2 ml. of HCL. Heat the solution to boiling and stir gently then add warm Bacl2 solution slowly until precipitation appears to be complete then add about 2 ml. in excess. Digest the precipitate on a water bath at 80 to 90 deg C, not less than 2 hours. Filter through a filter paper or through gooch crucible and wash with hot distilled water until washings are free from chlorides. Dry the filter paper and precipitate and ignite at 800 deg. C for 1 hr. Do not let the filter paper flame. Cool in a desicator and weigh.
Calculation
Sulphate as SO4 mg/lit = mg BaSO4 * 411.5
ml. of sample
EDTA METHOD(METHOD B)
A measured excess of standard barium chloride solution is added to the sample & the excess barium chloride estimated by titration against standard EDTA solution.
REAGENTS
1. Approx. 1N nitric acid
2. Standard barium chloride solution.
3. pH-10 buffer solution.
4. EBT indicator.
5. 0.01 M EDTA solution
PROCEDURE
Neutralise 100 ml. of the sample with dilute nitric acid, adding a slight excess , & boil off to expel carbon dioxide. Add 10 ml. or more if required, of standard barium chloridesolution to boiling solution & allow it to cool. Dilute to 200 ml. mix & allow precipitate to settle. Withdraw 50 ml. of the supernatant liquid, add 0.5 ml. to 1.0 ml. of buffer & several drops of indicator solution. Titrate with standard EDTA solution to a blue colour which does not change on addition of further drops of EDTA solution.
Calculations
sulphates, as SO4, mg/lit = 9.6 (0.1A+B - 4C )
where:
A = Total hardness of sample (as CaCO3 mg/lit )
B = Volume in ml. of standard barium chloride solution added
C = Volume in ml. of standard EDTA solution required for titration
NOTE:
1. It is very difficult to judge the endpoint of titration of barium against EDTA using EBT as indicator. It is preferable to use standard MgCl2 solution along with BaCl2 for Bacl2 standardisation ( or use a mixture of BaCl2 + MgCl2 solutions, instead of BaCl2 solution for precipitate of sulphate ion ).
2. It is also desirable to add MgCl2 solution, whenever, sample is low in Mg ions as in the case of decationized water.

SILVER NITRATE METHOD (CHLORIDE METHOD A)

Chloride is determined by titration with std. silver nitrate solution in the presence of potassium chromate indicator at neutral Ph. Silver chloride is precipitated and at the end point red silver chromate is formed.
REAGENTS
1. N Std. silver nitrate solution
2. Potassium chromate indicator
3. Phenolthalein Indicator solution
4. N Nitric Acid solution
5. Calcium carbonate
PROCEDURE
Take 50 ml. or 100 ml of sample in an Erlenmeyer flask. Add five drops of phenolthalein. If the sample turns pink, Neutralise with 0.02 N Nitric acid. If Acidic (as in the case of decationised water) add a small amount of A.R. calcium carbonates. Add 1 ml of potassium chromate indicator and titrate with std. silver nitrate solution with constant. stirring until there is perceptible reddish colour. Subtract 0.2 ml. from titration fig. to allow for the excess of reagents required to form silver chromate.
Calculation
Chloride as CaC03 mg/lit = ml of AgN03 * 1000
ml of sample taken
NOTE
1. If sample is highly coloured , add AL(OH)3 suspension, mix then let it settle , filter and combine filtrate and washing
2.If sulphide, sulphite and thiosulfate is present, add 1ml H2O2 and stir for 1Min.
3. Bromide, iodide and cyanide register as Eqvt. chloride concentration.

METHOD B
Chloride ion can be titrated with mercuric nitrate because of the formation of soluble, slightly dissociated mercuric chloride. In the Ph range 2.3 to 2.8 diphenylcarbozone indicates the end point of this titration by formation of purple complex with excess of mercuric ions. To keep the solution in Ph range +/- 0.1 Ph unit nickel nitrate with HNO3 is added .
REAGENTS
1. 0.02 N Mercuric nitrate Std. solution
2. Diphenyl-carbozone indicator solution
3. 4 M nickel nitrate solution
PROCEDURE
Take 50 ml. of sample , add 1 ml. of diphenylcarbozone indicator solution. Add 1 ml. of nickel nitrate solution. Titrate against Std. mercuric nitrate solution to colour change of green to violet. Carry out blank titration with DM Water.
Calculation
Chloride as CaCO3 mg/lit = (A - B ) * 1000
ml. of sample
where , A = ml of titrant required for sample
B = ml of titrant required for blank.
CHLOROMETRIC FOR CHLORIDE (MERCURY THIOCYNATE) METHOD C:-
This method depends upon the displacement of thiocynate ion from mercuric thiocynate by chloride ion. In the presence of ferric ion, a highly coloured ferric thiocynate complex is formed and the intensity of its colour is proportional to the original chloride ion concentration.
REAGENTS
1. Mercuric thiocynate solution
2. Ferric ammonium sulphate solution
3. Std. sodium chloride solution -0.1 mgCl / ml.
PROCEDURE
Take 10-20 ml of water sample containing about 40 micrograms of chloride in a 25 ml. std. flask. Add 2.0 ml of ferric ammonium sulphate solution, followed by 2.0 ml of mercuric thiocynate solution. Make up to the volume. Measure the optical density at 460 microsiemens From the calibration curve for the Std., compute the value for the sample.
Calculation
Chloride , as Cl mg /lit = Microgram of chloride from graph
ml. of sample


PHOSPHATE
A neutralised sample is reacted with ammonia molybdate & stannous chloride. The blue colour obtained is matched against that produced with a series of standard phosphate solutions, visually or with spectrometer at 690 micro.
REAGENTS
1. Phenolphthalein Indicator solution.
2. Approximately 4 N sulphuric acid.
3. Ammonium Molybdate solution.
4. Stannous chloride solution.
5. Standard phosphate solution.
PROCEDURE
To a 50 ml. sample containing not more than 0.15 mg. of phosphate (as PO4), add one drop of phenolphthalein indicator. If a pink colour is obtained, add dilute H2SO4 dropwise to discharge the colour. Add, with through mixing after each addition 2.0 ml. of ammonium molybdate solution & 0.25 ml. 5 drops of stannous chloride solution. The rate of colour development & intensity of colour depend upon the temperature of the final solution, each 1 Deg C increase producing about 1 percent increase in colour. hence samples & reagents should be within 2 deg . C of one another & at a temperature between 20 to 30 deg. C. After 10 min. but before 15 min., measure the colour photometrically or visually in a Nessler tubes against standards prepared simultaneously. A blank shall always be run on the reagents & distilled water.
Calculations
Phosphates as PO4 mg/lit = 1000 * w
V
where,
w = weight in mg. of phosphate (as Po4) in sample from standard graph (or solution).
V = Volume in ml. of sample taken.



OXYGEN CONSUMED FROM PERMANGANATE SOLUTION (CHEMICAL OXYGEN DEMAND)
This method is only an empirical measure of the organic matter. It gives some indication of the nature of the oxidisable substance present in the sample since nitrates, ferrous salts or sulphides will reduce the permanganate immediately whereas the organic matter reacts with the permanganate only after some time.It can be determined at room temperature by estimating the amount of standard KMnO4 solution consumed by the sample in 4 hours or at elevated temperature for a shorter period.
REAGENTS
1. N/10 standard KMnO4 solution.
2. N/10 standard oxalic acid solution.
3. (1: 3) sulphuric acid solution
PROCEDURE
Take 100 ml. of sample in conical flask. Add 10 ml. of 1:3 sulphuric acid solution & 10 ml. of N/10 standard KMnO4 solution is added to acidified sample. The sample is then boiled for exactly 10 min. Introduce 10 ml. of standard N/10 oxalic acid & while still hot titrate with standard KMnO4 slightly pink colour reappears
Calculations
Oxygen as KMnO4 consumed, mg/lit = ml. of KMnO4solution used up * 31.6
or
Oxygen, as Oxygen mg/lit = ml. of KMnO4 solution *8.0


OILS AND GREASE (OUTLINE OF THE METHOD)
The oils & grease are extracted by an organic solvent . The solvent is distilled off & the weight of the extracted matter is determined. Some extractable, especially unsaturated fats & fatty acids, oxidize rapidly hence, special precautions regarding temperature & solvent vapour displacement are necessary to minimise this effect.
SAMPLING
The most satisfactory method of sampling two - phase liquids is to use a sampling tube that is capable of withdrawing a complete section of the water as it flows in a rectangular culvert or trough, in most instances, however, water will have to be sampled from the outfall of the pipe or from a stream & in these circumstances some of the water should first be collected in a large cylindrical vessel having a capacity of 10 to 15 litres. A sectional sampling tube should be used to withdraw the test sample from this. A sampling tube suitable for sampling water, that don’t contain highly viscous matter ( for example, tar ) consist of a heavy - gauge brass tube , 1m. long , with an outside diameter of 40 mm. Over one end of the tube is fitted to the brass bucket made from a piece of tube 50 mm. long & sealed at one end. The bucket has an internal diameter of 1.5 mm. greater than the outside diameter of the main tube. To the opposite sides of the bucket, are braced two brass rods, 6mm. in diameter , which pass through guides braced to sides of the main tube. The rods are so arranged that the top of the bucket can be withdrawn to a distance of not less than 10 cm. from the bottom of the main tube, & they guide the bucket into a position covering the end of the tube when it is pushed back again.
A suitable spring catch is provided on one of the guide rods so that the bucket is automatically locked into the top position when it is raised to its highest point . The open end of the sampling tube is fitted with a rubber bung. To take a sectional sample , the spring catch is released & the bucket is drawn as far away as possible from the end of main tube. The rubber bung is withdrawn from the other end. The tube is lowered vertically through the liquid to the sampled until the bottom of the bucket rest on the bottom of the culvert or of the vessel that has been filled with the water. The main tube is then pushed down, guided by the brass rods, to the limits of his travel, whereupon the spring catch locks the bucket in the raised position covering the end of the tube. The rubber bung is tightly inserted in the open end & the tube is withdrawn.
The outside of the sampler is wiped free of adhering liquid the bucket & the lower part of the tube are inserted into a wide - mouthed bottle of suitable capacity, & the rubber bung is removed. The sample section of the liquid will flow into the bottle leaving a small quantity of liquid in the bucket . The tube is then tilted , so that this liquid is added to the main bulk of the sample. The operation is repeated until sufficient quantity has been collected. At least 24 - 25 mm. of air space should be left between the top level of the liquid & the stopper of the bottle.
STORAGE OF SAMPLE
Since many oils & hydrocarbons are utilised by bacteria , storage is obviously detrimental. However, if it becomes necessary to store the sample before analysis is taken up , the samples should be acidified with dilute sulphuric acid (1:1 ) , 5 ml / lit., of the sample, to inhibit bacterial activity .
APPARATUS
SEPARATING FUNNELS Of 1.5 to 2 litres capacity . The stopper or stop cock should not be lubricated with matter soluble in petroleum ether.
REAGENTS
1. Dilute Hydrochloric acid - 1 : 1
2. Light Petroleum (Petroleum ether) - boiling range 40 to 60C.
PROCEDURE
Place the sample, usually 1 litre, in a separating funnel of sufficient size to allow the addition of acid & solvent , & still have space for proper agitation. Acidify the sample with dilute hydrochloric acid, 5 ml /lit, of the sample. Rinse the sample bottle carefully with 15 ml. of petroleum ether & add the ether washings to the separating funnel. Add an additional 25 ml. of ether to the sample bottle, rotate the ether in the sample bottle & add the ether to the separating funnel . Shake vigorously for 2 minutes . Allow the ether layer to separate. Withdraw the aqueous portion of the sample into a clean container , & transfer the solvent layer into a clean, tarred distilling flask capable of holding at least 3 volumes of solvents(See Note).If a clear ether layer cannot be obtained, filter the solvent layer into tarred distilling flask through a funnel containing an ether moistened filter paper. The filter paper should be washed with petroleum either after folding to avoid inclusion of skin oils. Use a small funnel and filter paper as practical.
NOTE: While transferring the solvent layer from the separating funnel, a small quantity of it remains at the stem of the separating funnel, it is advisable to wash it with a few millilitre’s of solvent and to add the washings to the solvent layer. Return the aqueous portion of the sample to the separating funnel, rinsing the container with 15 ml. of ether. Add the ether washings and additional 25 ml. of ether to the separating funnel and agitate for about 2 Min. Allow the solvent layer to separate and discard the aqueous phase. Add the ether washings to the tarred distilled flask . After all the ether from the 2 extractions and the final rinsing are included wash down the funnel and filter paper twice with fresh 5 ml. increments of the petroleum ether.
Distil of all but approx. 10 ml. of the ether extract on a water batch or an electric heating mantle, observing necessary safety precautions and keeping the heat source at about 70 Deg c. Disconnect the condenser and boil of the remaining the solvent from the tarred flask at the same temp. Dry on a water bath or stream bath. When dry ,lay the flask on its side to facilitate the removal of solvent vapour. Introduce Aprrox. 3 volumes of dry illuminating gas or Nitrogen into flask to displace solvent vapour . Cool in desiccator for 30 Min. and weigh.
Calculation
Oils And grease , mg/lit = 1000 W
V
Where,
W = weight in Mg. of the residue in the flask
V = volume in ml. of the sample taken for the test.
Express the result to the nearest Mg



RESIDUAL CHLORINE (ORTHOTOLYDINE - ARSENI METHOD)
Chlorine rapidly oxidises ortholydine (3,3-dimethybenzdine) to the corresp. hologuinone which is intensely yellow. This provides a sensitive test for available chlorine. The test is subject to interference by production of false colour for chlorine when nitrite ,iron or manganese is present in the water. The false colour produced with orthotoludine by interfering substance present in the presence of sodium arsenite but the colour due to residual chlorine does not. The test permits the measurement of the relative amounts of free available chlorine, combined available chlorine ,and colour due to interfering substances. The temperature of the sample should never be above 20 deg C.
REAGENTS
1. Phosphate buffer solution -0.5%
2. Potassium dichromate solution
3. P-Tolydine reagent
4. 5 % sodium arsenite solution
PROCEDURE
1.VISUAL STANDARDS:- Pipette into 100 ml. Nessler cylinder 1,2,3 etc. ml of dilute chromate- dichromate solution an dilute to 100 ml with phosphate . Protect the solutions from dust, evaporation and direct sunlight. These Stds. correspond to residual chlorine Eqvt. of 0.01, 0.02 ,0.03.... mg/lit Resp.
2.FREE AVAILABLE CHLORINE:-In a nessler tube take 0.5 ml of Toludine reagent and 9.5 ml of sample . Mix quickly and thoroughly and add 0.5 ml of NaAS02 followed by mixing. Compare the colour with Std. (Call this reading as A).
3. TOTAL AVAILABLE RESIDUAL CHLORINE:- In a nessler tube take 0.5 ml of 0-Toludine reagent and 9.5 ml of sample, mix and compare the colour with standards colour in similar tube after 5 Min. (Call this reading as B).
4. BLANK:-Prepare a blank 9.5 ml sample and 0.5 ml NaAS02 solution and compare the colour with std. colour immediately and after 5 Min. (Call this reading as C1 and C2).
Calculation
Free available residual chlorine = Reading A - Blank C1
Combined available residual chlorine = Reading B - Blank A
Total available residual chlorine = Reading B - Blank C2
REAGENTS
1. STANDARD 1 N HCL SOLUTION :- Dilute 83 ml. of conc. HCL (about 11 N solution, specific gravity 1.174-1.189 ) to 1lit. with distilled or deionised water . Standardise with standard sodium carbonate solution.
2. STANDARD 0.1 N HCL SOLUTION :-Dilute 8.3 ml. of conc. Hcl or 100 ml. of 1 N solution to 1000 with distilled water. Standardise with standard sodium carbonate solution.
3. STANDARD 0.02 N Hcl SOLUTION. :-Dilute 200 ml. of 0.1 N standard acid to 1000 ml. with distilled water. Standardize with standard sodium carbonate solution
4. STANDARD 1 N H2SO4 SOLUTION :-Dilute 28 ml. of conc. H2SO4 (about 36 N solution, specific gravity 1.834-1.836 ) to 1lit. with distilled or deionised water. Standardise with standard sodium carbonate solution.
5. STANDARD 0.1 N H2SO4 SOLUTION:-Dilute 2.8 ml. conc. H2SO4 to 1 lit. with distilled or deionised water. Standardise with standard sodium carbonate solution.
6. STANDARD 0.02 N H2SO4 SOLUTION:-Dilute 200 ml. of 0.01 N H2SO4 to 1 lit. with distilled or deionised water. Standardise with standard sodium carbonate solution.
7. 1.0 N HNO3 SOLUTION :-Dilute 64 ml. of conc. HNO3 (about 15 N solution, specific gravity 1.409-1.418) to 1lit. with distilled or de ionised water. Standardise with standard sodium carbonate solution.
8. STANDARD I.0 N NAOH SOLUTION:-Dissolve 40.0 gm. of NAOH to 1.0 lit. with carbon dioxide free distilled or deionised water . Standardise with standard acid solution.
9. STANDARD 0.1 N NAOH SOLUTION:-Dissolve 4.0 gms of NAOH to 1.0 lit. with carbon dioxide free distilled or deionised water. Standardise with standard acid solution.
10. STANDARD SODIUM CARBONATE SOLUTION:-(Approx. 0.05 N ) Dry 3 to 5 g primary standard Na2 CO3 at 250 deg C for 4 hours & cool in a desiccators. Weigh 2.5 +/- 0.2 gms (to the nearest mg) Dilute to 1litre with deionised or distilled water.
11. STANDARD 0.02 N SILVER NITRATE SOLUTION.:-Dissolve 3.3927 gms. AgNO3 in distilled water & dilute to 1 lit. Standardise against 0.02 N NaCl standard solution.
12. STANDARD 0.02 N SODIUM CHLORIDE SOLUTION :-Dry 2-3 g of primary standard NaCl at 140 deg C for 4 hours & cool it in a desiccators. Weigh 1.689 gms (to the nearest mg. ) Dilute to 1litre with deionised or distilled water.
13. STANDARD 0.02 N MERCURIC NITRATE SOLUTION:-Dissolve 3.246 gm. mercuric nitrate in 100 ml of 5% HNO3 solution & make up to 1 lit. with D.M. water. Standardise with standard sodium carbonate solution.
14. STANDARD MERCURIC THIOCYANATE SOLUTION :-Weigh 1 gm Hg(SCN) 2 & add 100 ml methanol & mix to obtain a saturated solution. store in a amber bottle in a cool place.
15. FERRIC AMMONIUM SULPHATE:-Dissolve 12 g of Fe (NH4)2(SO4) 2. 12H2O in 100 ml of 9 N HNO3 (580 ml. of conc. HNO3 in 1 lit. of water ). Filter if necessary & store in a amber bottle.
16. 0.1 mg/Lit. STANDARD CHLORIDE SOLUTION:-Dissolve 1. 1648 g NaCl in 1 lit. of distilled or deionised water.
17. AMMONIA BUFFER OH pH 10:- Dissolve 16.9 g of ammonium chloride in 143 ml. conc. ammonium hydroxide (NH4OH). Add 1.25 g of magnesium salt of EDTA. (If the magnesium salt of EDTA is unavailable dissolve 1.179 g disodium salt of EDTA & 780 mg. MgSO4.7H2O or 644mg. MgCl2.6H2O in 50 ml. distilled water.) & dilute to 250 ml. with distilled water.
18. STANDARD 0.01 M SOLUTION OF EDTA:-Dissolve 3.723 g of disodium salt of EDTA in 1 lit. of distilled or deionised water. Standardise with standard calcium solution.
19. STANDARD CALCIUM SOLUTION:-Weigh 1 gm anhydrous calcium carbonate into a beaker, add a little at a time, dilute Hydrochloric acid until CaCO3 has dissolved. Wash down the beaker with carbon dioxide free water & makeup to 1 lit. 1 ml. of the solution contains 1mg of sulphate (as SO4)
20. STANDARD BARIUM CHLORIDE SOLUTION:-Dissolve 2.443 g of barium chloride (BaCl2, 2H2O) in distilled water & dilute to 1 lit. 1 ml. of this solution is equivalent to 0.36 mg. of sulphate (as SO4).
21. STANDARD POTASSIUM IODATE -IODATE SOLUTION:-Weigh accurately 0.713 g of potassium iodate & dissolve in about 150 ml. of distilled water. Add 7 g of potassium iodate & 0.5 g of sodium bicarbonate ,when dissolved, dilute the solution to exactly 1 liy.
22. STANDARD IRON SOLUTION:-Dissolve 1.404 g of ferrous ammonium sulphate Fe(NH4)2(SO4)2, 6H2O in 50 ml. distilled water & 20 ml. conc. H2SO4. Add 0.1 N KMNO4 dropwise to impart a faint but persistent pink colour & dilute to 1 lit. with distilled eater. Dilute 50 ml. of the above stock solution to 1 lit. with distilled water to form a standard solution containing 0.01 mg. fe/ml.
23. 1,10 PHENANTHROLINE MONOHYDRATE SOLUTION:-Dissolve 0.1 g in 100 ml. distilled water containing 2 drops conc. Hcl . (Not more than 0.1 mg. Fe can be determined).
24. AMMONIUM ACETATE BUFFER SOLUTION:-Dissolve 250 g of ammonium acetate in 150 ml. distilled water, add 700 ml. glacial acetic acid & dilute to 1 lit.
25AMMONIUM MOLYBDATE SOLUTION FOR SILICA ESTIMATION:-75 g of ammonium molybdate is dissolved in 500 ml. of distilled water. To 322 ml. of 10 N sulphuric acid molybdate solution is added gradually with constant stirring. The solution is made upto 1 lit.
26. 10% OXALIC ACID:-Dissolve 10 gms. oxalic acid in 100 ml. of distilled water.
27. AMINO NAPHTHOL REDUCING AGENT :-Dissolve 0.5 g of 1 amino-2-naphthol-4sulphonic acid & 1gm. of sodium sulphite (Na2SO3) in 50 ml. distilled water, with gentle warming if necessary, add this to solution of 30 g sodium metabisulphite (NaHSO3)in 150 ml. distilled water. Filter into plastic bottle. Dicard the solution when it becomes dark. prolong reagent life by sorting in a refrigerator.
28. STOCK SILICA SOLUTION:-Dissolve 4.73 g of sodium metasilicate nonhydrate (Na2SiO3, 9H2O) in recently boiled & cooled water & dilute to approx. 900 ml. Analyse 100.0ml. portions by gravimetric method, adjust the remainder of the solution to contain 1.000 mg./1SiO2. Store in a tightly stoppered plastic bottle.
29. STANDARD SILICA SOLUTION:-Dilute 10 ml. stock solution to 1 lit. with recently boiled & cooled water this solution contains 10 mg/lit. Sio2 or 1 ml. =10 Sio2. Store in a tightly stoppered plastic bottle.
30. AMMONIUM MOLYBDATE SOLUTION FOR PHOSPHATE ESTIMATION:-Dissolve 25 gms. of ammonium molybdate in 175 ml. of distilled water. In another container add, cautiously to 400 ml. of distilled water, 310 ml. of conc. H2SO4. Cool it & add the molybdate solution to this distilled acid & dilute the whole to 1 lit.
31. STANNOUS CHLORIDE SOLUTION:-Dissolve 2.5 gms. of fresh supply of stannous chloride (SnCl2,2H2O) in 10 ml. of conc. Hcl & dilute to 100 ml. with distilled or deionised water. Filter if it is turbid. Store the solution in a cool place in a aspirator bottle having class stopcock. A 5 mm. thick layer of pure mineral oil shall be floated over the surface of the solution to minimise oxidation. Always drain out a little of solution out of the stopcock before use.
32. STANDARD PHOSPHATE SOLUTION:-Dissolve 0.716 g of dry potassium dihydrogen phosphate (KH2PO4) in 1 lit. of distilled water. Dilute 100 ml. of solution to 1lit. 1ml. of this solution =0.05 mg of phosphate (as PO4 ).
33. STANDARD 0.1 N POTASSIUM PERMANGANATE SOLUTION:-Dissolve 3.1608 g of potassium permanganate (dried at 105 deg C ) in distilled water made upto 1 lit. This solution must be stored in the dark.
34. STANDARD 0.1 N OXALIC ACID SOLUTION:-Dissolve 4.5018 g of oxalic acid in distilled water, make upto 1lit.
35. PHOSPHATE BUFFER SOLUTION O.5 M (FOR FREE CHLORINE):-Dissolve 22.68 g Na2HPO4 & 46.19 g KH2PO4 (both dried overnight at 105 deg C) & dilute to 1 lit. with distilled water. Let this solution age for No. of days & filter if any precipitate appears.
36. PHOSPHATE BUFFER SOLUTION 0.1 M:-Dilute 200 ml. of 0.5 M filtered phosphate buffer solution to 1 lit.
37. STOCK CHROMATE- DICHROMATE SOLUTION:-Dissolve 1.55 g K2Cr2O7 & 4.65 g K2CrO4 in 0.1 M phosphate buffer solution.
38. DILUTE CHROMATE DICHROMATE SOLUTION:-Dilute 100 ml. stock solution to 1 lit. with 0.1 M phosphate buffer solution. On dilution of 1ml. of this solution to 100 ml. with 0.1 M phosphate buffer solution gives a very close visual match with the yellow colour produced by 0.01 mg/lit. residual chlorine.
39. O-TOLUDINE REAGENT:-Dissolve 1.35 g of O-toludine dihydrogen chloride in 500 ml. distilled water & add with constant stirring to a solution of 150 ml. conc. Hcl in 350 ml. distilled water.
40. SODIUM ARSENITE SOLUTION:-Dissolve 5 g of sodium meta arsenite in 1lit. distilled water.
41. PHENOLPHTHALEIN INDICATOR SOLUTION:-Dissolve 0.1 g of phenolphthalein in 60 ml. of rectified spirit & dilute with distilled water to 100 ml.
42. METHYL ORANGE INDICATOR SOLUTION:-Dissolve 50 mg. methyl orange powder in distilled water & dilute to 100 ml.
43. SCREENED METHYL ORANGE INDICATOR SOLUTION:-Dissolve 0.2 g crystalline methyl orange in a mixture of 25 ml. of methylated spirit & 25 ml. of deionised water. Dissolve 0.28 g xylene cyanol FF in a mixture of 25 ml. of methylated spirit & 25 ml. deionised water. Mix the two solutions together.
44. 5% POTASSIUM DICHROMATE INDICATOR SOLUTION:-Dissolve 50 g K2CrO4 in little distilled water. Add Silver Nitrate solution until a definite red precipitate is formed. Let it stand for 12 hr. filter & dilute to 1 lit with distilled water.
45. SODIUM THIOSULPHATE 0.1 N SOLUTION:-Dissolve 25 gm Na2S2O3,5H2O & dilute to 1 lit. with distilled water.
46. DIPHENYL CARBAZONE INDICATOR SOLUTION:-Dissolve 0.4 g of di phenyl carbazone in 100 ml. of 95% is propanol
47. 4 M NICKEL NITRATE SOLUTION.:-Dissolve 1163 gms. of nickel nitrate (Ni(NO3)2,6H2O)in 1 lit. of D.M. water.
48. ERIOCHROME BLACK T INDICATOR SOLUTION:-Mix 0.5 g of sodium salts of Eriochrome Black T ( 1- hydroxy-2-naphthylazo)-5-nitro-2-naphthol-4-sulphonic acid) with 4.5 gms hydroxylamine hydrochloride. Dissolve this mixture in 100 ml. of 95% ethyl or isopropyl alcohol.
a) Mix together 0.5 g dye & 100 g NaCl to prepare a dry powder mixture.
49. MUREXIDE INDICATOR SOLUTION
a) Dissolve 150 g of Murexide (ammonium purpurate) in 100 g of absolute ethylene glycol. Water solution of the dye is not stable for longer than a day.
b) Mix 200 mg. of murexide with 100 gms. of solid NaCl & grinding the mixture to 40 to 50 mesh.
c) Titrate immediately after adding the indicator because it is unstable under alkaline conditions.
50. STARCH INDICATOR SOLUTION:-Dissolve 5 gms of starch & 0.01 gms of mercuric iodide with 30 ml. of cold distilled water & slowly pour it with constant stirring into 1 lit. of boiling distilled water. Boil for 3 min & allow it to cool then decant off the supernatant clear liquid.


51.HYDROXYLAMINE HYDROCHLORIDE SOLUTION FOR Fe :-Dissolve 10 gms. NH2OH & HCl in 100 ml. distilled water.