Monday, 21 September 2015

Biopreneur: Biotoilet

Biopreneur: Biotoilet: Selection of technology for sewage treatment should be on criteria such as plant which work without electricity, require minimum maintena...

Wednesday, 16 September 2015

BIRAC Announces Third Call for SPARSH - Innovative Technology Solutions for Waste to Value (15 Aug - 30th Sept, 2015)

Request for proposals for Technological interventions for conversion of faecel sludge and MSW to energy and other products
SPARSH is the, Social Innovation programme for Products: Affordable & Relevant to Societal Health

BIRAC, a Public Sector Undertaking of Department of Biotechnology, Ministry of Science and Technology, Government of India launched this programme highlighting the need of Innovative solutions to society’s most pressing social problems. The scheme tackles major social issues and offers new ideas for wide-scale change.

The scheme aims to invest in ideas and innovations that improve the health and well-being of all Indians and provides affordable product development in the social sector. The scheme also targets creating a pool of Innovators who identify the specific needs and gaps in critical sector and then work towards funding innovative solutions. The social innovators are supported for developing market-based solutions that have a potential to bring breakthrough technologies and product to vulnerable populations.
For more information on the programme please refer to Concept Note
Last date for Submission : 30th September, 2015
Innovation technology solutions for wadte to value

Saturday, 11 July 2015

Digital India Week 1st - 7th July, 2015

The objective of Digital India Programme during the Digital India Week is to Inform, Educate and Engage citizens in the ongoing government efforts to transform India into digitally empowered society and knowledge economy. Hon'ble Prime Minister launched this Programme  on 1st July, 2015.

The 3i Portal received the CSI Nihilent e-Governance Award 2013-14


http://www.birac.nic.in/edituploads/1418739044_award_csi.jpg

BIRAC was conferred the CSI Nihilent e-Governance Award 2013-14 for its 3i Portal. The 3i – “Investment for Industry Innovation Research” – Portal has been developed for sustainable, accountable, transparent governance and management of the Investment Schemes of national importance run and managed by BIRAC.

BIRAC Announces Call for Proposals under BIPP and SBIRI Scheme

Dainik Bhaskar India Pride Awards 2014-15: BIRAC won accolades with Special Award in Biotechnology Sector



Sunday, 19 April 2015

Vacancies in BIRAC- Last Date is 20 April,2015.





Biotechnology Industry Research Assistance Council
(A Govt. of India Enterprise)
Set up by Department of Biotechnology, Ministry of Science & Technology, Govt. of India

Vacancy: Administrative & Finance Officer in the DBT – BMGF – BIRAC,
Project Management Unit at BIRAC, New Delhi, India.

  1. Applications are invited from qualified and experience professionals for the position of Administrative & Finance Officer in the DBT – BMGF – BIRAC, Project Management Unit at BIRAC, New Delhi, India.

  2. THE DBT – BMGF – BIRAC Partnership: The Bill and Melinda Gates Foundation (BMGF) and the Department of Biotechnology (DBT) signed an umbrella Memorandum of Understanding (MoU) to collaborate on mission-directed research and build Grand Challenges India to support health research and innovation. The MoU aims to support initiatives that could dramatically change the health and development landscape in India and other countries facing similar challenges. Biotechnology Industry Research Assistance Council (BIRAC) a public section undertaking of Department of Biotechnology, Ministry of Science & Technology, and Government of India has been entrusted the responsibility of implementing this activity. BIRAC plays a key role in assisting the Global network of Partners to foster collaborative research to improve Global health and dealing with long term development issues.

  3. The Program Management Unit (PMU), is the implementing body to manage the Grand Challenges India program. The partners have laid down the governance and implementation principles that will direct these strategic partnerships. BIRAC works closely with strategic partners to identify and support the scientific and technological opportunities through PMU. The PMU while being responsible for project management is also responsible for an oversight of various joint projects funded under Grand Challenges India.

  4. The Position Summary & Key Responsibilities are as under:
    1. The position of Administrative & Finance Officer will be reporting to the Head, Program Management Unit (PMU), BIRAC and will be overall responsible for all administrative and financial matters related to the Project Management Unit and the programmes and project being handled.
    2. The Key Responsibilities are as under:
    • Take care of all logistic requirement, arranging meetings, visits, etc.
    • Work with HR and Administration to provide administrative support.
    • Manage the work of back office.
    • Administer housekeeping activities in the office and manages other logistics.
    • Maintain records, prepare reports and composes correspondence related to work.
    • Oversee the daily accounting activities required to maintain the general ledger.
    • Maintain organized set of detailed records and files to document financial transactions.
    • Maintain all details of project accounts.
    • Responsible for releases and all financial transactions in respect of project grants.
    • Timely submission of financial report.


  5. Qualifications and Experience
    • Graduate Degree from a recognized and reputed institute. M. Com / MBA from a recognized and reputed institute will be preferred.
    • 3-6 years experience in accounts / admin department of a private/public sector/government/not-for-profit/international organization.
    • Good written and oral communication skill.
    • Ability to interact with all funding partners and grantees for finalizing the documents.
    • Ability to work with efficiency both individually and as a team.
    • Should have highest level of integrity.


  6. Salary commensurate with qualifications and experience will be as under:
Levels
Experience
Salary Range
Level I
3-5 years
38,000 – 56,000
Level II
5-8 Years
57,000 – 74,000
                 The tenure of appointment will be for three years or co-terminus with the project whichever is earlier.
                 Interested candidates should apply at vacancy.birac@nic.in in the prescribed format enclosed as                              Document 1.
                 Age Limit is 45 years as on 01.04.2015. Last date for application is 20th April, 2015. Hard copies of the                  application will not be accepted / considered.

Sunday, 22 March 2015

Press Release - An Equity Fund to Address to Accelerate the Growth of Entrepreneurs, in the field of Biotechnology Launched

Press Information Bureau
Government of India
Ministry of Science & Technology 
19-March-2015 18:00 IST
An Equity Fund to Address to Accelerate the Growth of Entrepreneurs, in the field of Biotechnology Launched 
The Minister of State for Science & Technology and Earth Sciences Shri Y.S. Chowdary today announced launching of–“BIRAC AcE Fund”. The Equity Fund is aimed at addressing the pressing needs of accelerating the growth of entrepreneurs, in the field of Biotechnology. This fund will be operated by Biotechnology Industry Research Assistance Council (BIRAC) a Public Sector Undertaking under the Department of Biotechnology, Ministry of Science & Technology, Government of India with Incubators and Business Accelerators, as its partners. Speaking on the occasion of the third foundation day of BIRAC in New Delhi today, the minister expressed hope that this major step taken by the Government would dramatically change the landscape of the Biotech startup ecosystem in the country. He said that this is important and a major decision wherein the Government will be a partner in Equity Funding for Start Up’s. The Minster also mentioning several budgetary provisions that are aimed at encouraging self employment and start ups said that a help-desk is proposed to be set up in his ministry for people wanting to know of these schemes.


Earlier the Minister for Science & Technology and Earth Sciences Dr. Harsh Vardhan who was abroad for attending the Science & Technology Minister’s Conference of Brazil, Russia, India, China and South Africa (BRICS) in Brazil gave his message to the Conference. He said recent success stories in the field of biotechnology in India and also increased budgetary allocations by the Government for innovation in the form of ATAL Innovation Fund etc. makes him believe that the target set for the biotechnology sector will be achieved.

Shri Y.S. Chowdary also inaugurated a Two day Panel discussions, to make biotechnology one of the drivers of the ‘Make in India’ Programme. The theme for the foundation day is “Accelerating Innovations: India the Next Biotech Global Hub”. Several eminent speakers from the field of Biotechnology including senior bureaucrats from DIPP, ICMR, Department of Pharmaceuticals and Senior Industry Leaders such as Dr Kiran Mazumdar-Shaw, CMD, Biocon will participate in panel discussions. Among themes for discussion are topics like - India the next Global Biotech Hub: The status of our readiness?, India a Bio-manufacturing Hub: Bridging the Paradigm for Quality and Affordability, Leveraging Partnerships to Make in India : Collaborating with national and international partners for enhanced competency. A plenary talk on- ‘Make in India’: a Perspective on the Biotech Sector: the opportunities, the enablers and the challenges, is also scheduled to be delivered by the Chairman and Managing Director, Biocon Dr. Kiran Mazumdar Shaw.

Over 250 Scientists, Entrepreneurs & Industry Experts, and Policy Makers will participate. The focus of the discussion would be on India’s readiness to meet the challenges of “Make in India” in the Biotech sector.

BIRAC was established under the aegis of the Department of Biotechnology, Ministry of Science & Technology, Government of India as a Public Sector Undertaking three years ago and is mandated to foster and promote innovation research in biotech industries specially start-ups and SMEs. Today, BIRAC has more than 100 Young Entrepreneurs, nearly 250 companies and start-ups and 15 incubators supported as an important part of the Innovation ecosystem of the country.

Friday, 13 February 2015

Chloride Test in Wastewater



Introduction :
Chloride, in the form of chloride (Cl ~) ion, is one of the major inorganic anions in water and wastewater. The salty taste produced by chloride concentrations is variable and dependent on the chemical composition of water. Some waters containing 250 mg C1~/L may have a detectable salty taste if the cation is sodium.
On the other hand, the typical salty taste may be absent in waters containing as much as 1000 mg/L when the predominant cations are calcium and magnesium.

The chloride concentration is higher in wastewater than in raw water because sodium chloride (NaCl) is a common article of diet and passes unchanged through the digestive system. Along the sea coast, chloride may be present in high concentrations because of leakage of salt water into the sewerage system. It also may be increased by industrial processes.

A high chloride content may harm metallic pipes and structures, as well as growing plants.

Selection of Method

Six methods are presented for the determination of chloride. Because the first two are similar in most respects, selection is largely a matter of personal preference. The argentometric method (B) is suitable for use in relatively clear waters when 0.15 to 10 mg Cl~ are present in the portion titrated. The end point of the mercuric nitrate method (C) is easier to detect. The potentiometric method (D) is suitable for colored or turbid samples in which color-indicated end points might be difficult to observe. The potentiometric method can be used without a pretreatment step for
samples containing ferric ions (if not present in an amount greater than the chloride concentration), chromic, phosphate, and ferrous and other heavy-metal ions. The ferricyanide method (E) is an automated technique. Flow injection analysis (G), an automated colorimetric technique, is useful for analyzing large numbers of samples. Preferably determine chloride by ion chromatography (Section 4110). Chloride also can be determined by the capillary ion electrophoresis method (Section 4140). Methods (C and G) in which mercury, a highly toxic reagent, is used require special disposal practices to avoid improper sewage discharges. Follow appropriate regulatory procedures (see Section 1090).

Sampling and Storage
Collect representative samples in clean, chemically resistant glass or plastic bottles. The maximum sample portion required is 100 mL. No special preservative is necessary if the sample is to be stored.

B. Argentometric method

1. General Discussion
a. Principle: In a neutral or slightly alkaline solution, potassium chromate can indicate the end point of the silver nitrate titration of chloride. Silver chloride is precipitated quantitatively before red silver chromate is formed.

b. Interference: Substances in amounts normally found in potable waters will not interfere. Bromide, iodide, and cyanide register as equivalent chloride concentrations. Sulfide, thiosulfate, and sulfite ions interfere but can be removed by treatment with hydrogen peroxide. Orthophosphate in excess of 25 mg/L interferes by precipitating as silver phosphate. Iron in excess of 10 mg/L interferes by masking the end point.

2. Apparatus

a. Erlenmeyer flask, 250-mL.
b. Buret, 50-mL.

3. Reagents

a. Potassium chromate indicator solution: Dissolve 50 g K2CrO4 in a little distilled water. Add AgNO3 solution until a definite red precipitate is formed. Let stand 12 h, filter, and dilute to 1 L with distilled water.

b. Standard silver nitrate titrant, 0.0141M (0.0141A1): Dissolve 2.395 g AgNO3 in distilled water and dilute to 1000 mL. Standardize against NaCl by the procedure described in 11 4b below; 1.00 mL = 500 fig Cl~. Store in a brown bottle.

c. Standard sodium chloride, 0.0141M (0.0141AT): Dissolve 824.0 mg NaCl (dried at 140°C) in distilled water and dilute to 1000 mL; 1.00 mL = 500 jjig Cr.

d. Special reagents for removal of interference:

1) Aluminum hydroxide suspension: Dissolve 125 g aluminum potassium sulfate or aluminum ammonium sulfate, AIK(SO4)2-12H2O or A1NH4(SO4)2-12H2O, in 1 L distilled water. Warm to 60°C and add 55 mL cone ammonium hydroxide (NH4OH) slowly with stirring. Let stand about 1 h, transfer to a large bottle, and wash precipitate by successive additions, with thorough mixing and decanting with distilled water, until free from chloride. When freshly prepared, the suspension occupies a volume of approximately 1 L.

2) Phenolphthalein indicator solution.

3) Sodium hydroxide, NaOH, IN.

4) Sulfuric acid, H2SO4, IN.

5) Hydrogen peroxide, H2O2, 30%.

4. Procedure

a. Sample preparation: Use a 100-mL sample or a suitable portion diluted to 100 mL. If the sample is highly colored, add 3 mL A1(OH)3 suspension, mix, let settle, and filter. If sulfide, sulfite, or thiosulfate is present, add 1 mL H2O2 and stir for 1 min.

b. Titration: Directly titrate samples in the pH range 7 to 10. Adjust sample pH to 7 to 10 with H2SO4 or NaOH if it is not in this range. For adjustment, preferably use a pH meter with a nonchloride- type reference electrode. (If only a chloride-type electrode is available, determine amount of acid or alkali needed for adjustment and discard this sample portion. Treat a separate portion with required acid or alkali and continue analysis.) Add 1.0 mL K2CrO4 indicator solution. Titrate with standard AgNO3 titrant to a pinkish yellow end point. Be consistent in end-point recognition. Standardize AgNO3 titrant and establish reagent blank value by the titration method outlined above. A blank of 0.2 to 0.3 mL is usual.

5. Calculation
rag C1~/L =(A - B) X TV X 35450/mL sample

where:
A — mL titration for sample,
B = mL titration for blank, and
N = normality of AgNO3.

mg NaCl/L = (mg Cr/L) X 1.65

6. Precision and Bias

A synthetic sample containing 241 mg C1~/L, 108 mg Ca/L, 82 mg Mg/L; 3.1 mg K/L, 19.9 mg Na/L, 1.1 mg NO3--N/L, 0.25 mg NCV- N/L, 259 mg SO4 2~/L, and 42.5 mg total alkalinity/ L (contributed by NaHCO3) in distilled water was analyzed in 41 laboratories by the argentometric method, with a relative standard deviation of 4.2% and a relative error of 1.7%.

7. Bibliography

HAZEN, A. 1889. On the determination of chlorine in water. Amer. Chem. J. 11:409.

KOLTHOFF, I.M. & V.A. STENOER. 1947. Volumetric Analysis. 2nd ed.
Vol. 2. Interscience Publishers, New York, N.Y., pp. 242-245, 256-258.

PAUSTIAN, P. 1987. A novel method to calculate the Mohr chloride titration.
In Advances in Water Analysis and Treatment, Proc. 14th Annu. AWWA Water Quality Technology Conf., November 16-20, 1986, Portland, Ore., p. 673. American Water Works Assoc., Denver,Colo.


C. Mercuric Nitrate Method

1. General Discussion

a. Principle'. Chloride can be titrated with mercuric nitrate, Hg(NO3)2, because of the formation of soluble, slightly dissociated mercuric chloride. In the pH range 2.3 to 2.8, diphenylcarbazone indicates the titration end point by formation of a purple complex with the excess mercuric ions. Xylene cyanol FF serves as a pH indicator and end-point enhancer. Increasing the strength of the titrant and modifying the indicator mixtures extend the range of measurable chloride concentrations.

b. Interference: Bromide and iodide are titrated with Hg(NO3)2 in the same manner as chloride. Chromate, ferric, and sulfite ions interfere when present in excess of 10 mg/L.

2. Apparatus

a. Erlenmeyer flask, 250-mL.

b. Microburet, 5-mL with 0.01-mL graduation intervals.

3. Reagents

a. Standard sodium chloride, 0.0141M (0.01417V): See Method B, H 3c above.

b. Nitric acid, HNO3, 0.1 AT.

c. Sodium hydroxide, NaOH, 0.1 TV.

d. Reagents for chloride concentrations below 100 mg/L:

1) Indicator-acidifier reagent: The HNO3 concentration of this reagent is an important factor in the success of the determination and can be varied as indicated in a) or b) to suit the alkalinity range of the sample. Reagent a) contains sufficient HNO3 to neutralize a total alkalinity of 150 mg as CaCO3/L to the proper pH in a 100-mL sample. Adjust amount of HNO3 to accommodate samples of alkalinity different from 150 mg/L.

a) Dissolve, in the order named, 250 mg s-diphenylcarbazone, 4.0 mL cone HNO3, and 30 mg xylene cyanol FF in 100 mL 95% ethyl alcohol or isopropyl alcohol. Store in a dark bottle in a refrigerator. This reagent is not stable indefinitely. Deterioration causes a slow end point and high results.

b) Because pH control is critical, adjust pH of highly alkaline or acid samples to 2.5 ± 0.1 with 0.1/V HNO3 or NaOH, not with sodium carbonate (Na2CO3). Use a pH meter with a nonchloride type of reference electrode for pH adjustment. If only the usual chloride-type reference electrode is available for pH adjustment, determine amount of acid or alkali required to obtain a pH of 2.5 ±0.1 and discard this sample portion. Treat a separate sample portion with the determined amount of acid or alkali and continue analysis. Under these circumstances, omit HNO3 from indicator reagent.

2) Standard mercuric nitrate titrant, 0.007 05M (0.0141/V): Dissolve 2.3 g Hg(NO3)2 or 2.5 g Hg(NO3)2-H2O in 100 mL distilled water containing 0.25 mL cone HNO3. Dilute to just under 1 L. Make a preliminary standardization by following the procedure described in 11 4a. Use replicates containing 5.00 mL standard NaCl solution and 10 mg sodium bicarbonate (NaHCO3) diluted to 100 mL with distilled water. Adjust titrant to 0.0141/V and make a final standardization; 1.00 mL = 500 |_ig Cl ~. Store away from light in a dark bottle.

e. Reagent for chloride concentrations greater than 100 mg/L:

1) Mixed indicator reagent: Dissolve 0.50 g diphenylcarbazone powder and 0.05 g bromphenol blue powder in 75 mL 95% ethyl or isopropyl alcohol and dilute to 100 mL with the same alcohol.

2) Strong standard mercuric nitrate titrant, 0.0705M (0.141/V) Dissolve 25 g Hg(NO3)2-H2O in 900 mL distilled water containing 5.0 mL cone HNO3. Dilute to just under 1 L and standardize by following the procedure described in f 4b. Use replicates containing 25.00 mL standard NaCl solution and 25 mL distilled water. Adjust titrant to 0.141/V and make a final standardization; l.OOmL = S.OOmgCr.

4. Procedure

a. Titration of chloride concentrations less than 100 mg/L: Use a 100-mL sample or smaller portion so that the chloride content is less than 10 mg.

 Add 1.0 mL indicator-acidifier reagent. (The color of the solution should be green-blue at this point. A light green indicates pH less than 2.0; a pure blue indicates pH more than 3.8.) For most potable waters, the pH after this addition will be 2.5 ±0.1. For highly alkaline or acid waters, adjust pH to about 8 before adding indicator-acidifier reagent.

Titrate with 0.0141 N Hg(NO3)2 titrant to a definite purple end point. The solution turns from green-blue to blue a few drops before the end point.

Determine blank by titrating 100 mL distilled water containing 10 mg NaHCO3.

b. Titration of chloride concentrations greater than JOO mg/L: Use a sample portion (5 to 50 mL) requiring less than 5 mL titrant to reach the end point. Measure into a 150-mL beaker. Add approximately 0.5 mL mixed indicator reagent and mix well. The color should be purple. Add 0.1 AT HNO3 dropwise until the color just turns yellow. Titrate with strong Hg(NO3)2 titrant to first permanent dark purple. Titrate a distilled water blank using the same procedure.

5. Calculation

(A - B) X N X 35450
mg C1-/L = - '-
mL sample
where:
A = mL titration for sample,
B = mL titration for blank, and
N = normality of Hg(NO3)2.
mg NaCl/L = (mg Cr/L) X 1.65

6. Precision and Bias

A synthetic sample containing 241 mg C1~/L, 108 mg Ca/L, 82 mg Mg/L, 3.1 mg K/L, 19.9 mg Na/L, 1.1 mg NO3~-N/L, 0.25 mg NO2~-N/L, 259 mg SO4 2"/L, and 42.5 mg total alkalinity/ L (contributed by NaHCO3) in distilled water was analyzed in 10 laboratories by the mercurimetric method, with a relative standard deviation of 3.3% and a relative error of 2.9%.

7. Bibliography
KOLTHOFF, I.M. & V.A. STENGER. 1947. Volumetric Analysis, 2nd ed. Vol. 2. Interscience Publishers, New York, N.Y., pp. 334-335.
DOMASK, W.C. & K.A. KOBE. 1952. Mercurimetric determination of chlorides
and water-soluble chlorohydrins. Anal. Chem. 24:989.
GOLDMAN, E. 1959. New indicator for the mercurimetric chloride determination
in potable water. Anal. Chem. 31:1127.

D. Potentiometric method

1. General Discussion
a. Principle: Chloride is determined by potentiometric titration with silver nitrate solution with a glass and silver-silver chloride electrode system. During titration an electronic voltmeter is used to detect the change in potential between the two electrodes. The end point of the titration is that instrument reading at which the greatest change in voltage has occurred for a small and constant increment of silver nitrate added.

b. Interference: Iodide and bromide also are titrated as chloride. Ferricyanide causes high results and must be removed. Chromate and dichromate interfere and should be reduced to the chromic state or removed. Ferric iron interferes if present in an amount substantially higher than the amount of chloride. Chromic ion, ferrous ion, and phosphate do not interfere.
 Grossly contaminated samples usually require pretreatment. Where contamination is minor, some contaminants can be destroyed simply by adding nitric acid.

2. Apparatus

a. Glass and silver-silver chloride electrodes: Prepare in the laboratory or purchase a silver electrode coated with AgCl for use with specified instruments. Instructions on use and care of electrodes are supplied by the manufacturer.

b. Electronic voltmeter, to measure potential difference between electrodes: A pH meter may be converted to this use by substituting the appropriate electrode.

c. Mechanical stirrer, with plastic-coated or glass impeller.

3. Reagents

a. Standard sodium chloride solution, 0.0141M (0.0141A/): See K 4500-a~.B.3c.

b. Nitric acid, HNO3, cone.

c. Standard silver nitrate titrant, 0.0141A/ (0.0141A7): See 11 4500-C1-.B.36.

d. Pretreatment reagents:

1) Sulfuric acid, H2SO4, 1 + 1.

2) Hydrogen peroxide, H2O2, 30%.

3) Sodium hydroxide, NaOH, IN.

4. Procedure

a. Standardization: The various instruments that can be used in this determination differ in operating details; follow the manufacturer's instructions. Make necessary mechanical adjustments. Then, after allowing sufficient time for warm up (10 min), balance internal electrical components to give an instrument setting of 0 mV or, if a pH meter is used, a pH reading of 7.0.

1) Place 10.0 mL standard NaCl solution in a 250-mL beaker, dilute to about 100 mL, and add 2.0 mL cone HNO3. Immerse stirrer and electrodes.

2) Set instrument to desired range of millivolts or pH units. Start stirrer.

3) Add standard AgNO3 titrant, recording scale reading after each addition. At the start, large increments of AgNO3 may be added; then, as the end point is approached, add smaller and equal increments (0.1 or 0.2 mL) at longer intervals, so that the exact


end point can be determined. Determine volume of AgNO3 used at the point at which there is the greatest change in instrument reading per unit addition of AgNO3.

4) Plot a differential titration curve if the exact end point cannot be determined by inspecting the data. Plot change in instrument reading for equal increments of AgNO3 against volume of AgNO3 added, using average of buret readings before and after each addition. The procedure is illustrated in Figure 4500-C1~:1.

b. Sample analysis:
1) Pipet 100.0 mL sample, or a portion containing not more than 10 mg Cl~, into a 250-mL beaker. In the absence of interfering substances, proceed with H 3) below.

2) In the presence of organic compounds, sulfite, or other interferences (such as large amounts of ferric iron, cyanide, or sulfide) acidify sample with H2SO4, using litmus paper. Boil for 5 min to remove volatile compounds. Add more H2SO4, if necessary, to keep solution acidic. Add 3 mL H2C>2 and boil for 15 min, adding chloride-free distilled water to keep the volume above 50 mL. Dilute to 100 mL, add NaOH solution dropwise until alkaline to litmus, then 10 drops in excess. Boil for 5 min, filter into a 250-mL beaker, and wash precipitate and paper several times with hot distilled water.

3) Add cone HNO3 dropwise until acidic to litmus paper, then 2.0 mL in excess. Cool and dilute to 100 mL if necessary. Immerse stirrer and electrodes and start stirrer. Make any necessary adjustments according to the manufacturer's instructions and set selector switch to appropriate setting for measuring the difference of potential between electrodes.

4) Complete determination by titrating according to 11 4a4). If an end-point reading has been established from previous determinations for similar samples and conditions, use this predetermined end point. For the most accurate work, make a blank titration by carrying chloride-free distilled water through the procedure.

5. Calculation
mg
(A - B) X N X 35450
mL sample
where:
A = mL AgNO3,
B = mL blank, and
N = normality of titrant.

6. Precision and Bias

In the absence of interfering substances, the precision and bias are estimated to be about 0.12 mg for 5 ing Cl~, or 2.5% of the amount present. When pretreatment is required to remove interfering substances, the precision and bias are reduced to about 0.25 mg for 5 mg Cl~, or 5% of amount present.

7. Bibliography
KOLTHOFF, I.M. & N.H. FURMAN. 1931. Potentiometric Titrations, 2nd ed. John Wiley & Sons, New York, N.Y.
REFFENBURG, H.B. 1935. Colorimetric determination of small quantities of chlorides in water. Ind. Eng. Chetn., Anal. Ed. 7:14.
CALDWELL, J.R. & H.V. MEYER. 1935. Chloride determination. Ind. Eng. Chem., Anal. Ed. 7:38.
SERFASS, E.J. & R.F. MURACA. 1954. Procedures for Analyzing Metal- Finishing Wastes. Ohio River Valley Water Sanitation Commission, Cincinnati, Ohio, p. 80.
FURMAN, N.H., ed. 1962. Standard Methods of Chemical Analysis, 6th ed. D. Van Nostrand Co., Princeton, N.J., Vol. I.
WALTON, H.F. 1964. Principles and Methods of Chemical Analysis. Prentice-
Hall, Inc., Englewood Cliffs, N.J.
WILLARD, H.H., L.L. MERRITT & J.A. DEAN. 1965. Instrumental Methods of Analysis, 4th ed. D. Van Nostrand Co., Princeton, N.J.