1、BRITISH STANDARD CONFIRMED JULY1990 BS3762-3.16: 1985 Analysis of formulated detergents Part 3: Quantitative test methods Section 3.16 Method for determination of chloride content NOTEIt is recommended that this Section be read in conjunction with the information in the “General Introduction”, publi
2、shed separately as BS3762-0. UDC 661.185:543.257:546.161BS3762-3.16:1985 This BritishStandard, having been prepared under the directionof the Chemicals Standards Committee, was published under the authority ofthe Board of BSI and comes intoeffect on 31January1985 BSI12-1999 The committees responsibl
3、e for this BritishStandard are shown inPart0. The following BSI references relate to the work on this standard: Committee reference CIC/34 Draft for comment84/50246 DC ISBN 0 580 14134 9 Foreword This Section of BS3762 has been prepared under the direction of the Chemicals Standards Committee and su
4、persedes methodD5 of BS3762:1964. This standard describes a method of test only and should not be referred to as a specification defining limits of purity. Reference to the standard should indicate that the method of test used is in conformity with BS3762-3.16. A British Standard does not purport to
5、 include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover,
6、pagesi andii, pages1 and2, an inside back cover and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover. Amendments issued since publication Amd. No. Date of issue Comments
7、BS3762-3.16:1985 BSI 12-1999 i Contents Page Foreword Inside front cover 1 Scope 1 2 Principle 1 3 Reagents 1 4 Apparatus 1 5 Procedure 1 6 Expression of results 1 7 Test report 1 Publication referred to Inside back coverii blankBS3762-3.16:1985 BSI 12-1999 1 1 Scope This Section of BS3762 describes
8、 a method of analysis for the determination of chloride content of formulated detergents. The chloride content is expressed as sodium chloride. NOTEThe title of the publication referred to in this Section is given on the inside back cover. 2 Principle The chloride is directly titrated with silver ni
9、trate and a silver electrode is used to detect the end-point. 3 Reagents The reagents shall be of a recognized analytical reagent quality. Water complying with the requirements of BS3978 shall be used throughout. 3.1 Nitric acid solution, c(HNO 3 )=5mol/L. 3.2 Silver nitrate solution, c(AgNO 3 )=0.1
10、00mol/L. 3.3 Methyl orange indicator solution 4 Apparatus Ordinary laboratory apparatus and the following are required. 4.1 pH meter, or other apparatus suitable for potentiometric titrations. 4.2 Silver electrode 4.3 Mercury (I) sulphate reference electrode 5 Procedure 5.1 Test portion Weigh, to0.0
11、1g, approximately5g of the well mixed sample or proportionally less in the case of asample containing more than5% of chloride (asNaCl). 5.2 Determination Dissolve the test portion in50mL to100mL of water and add a few drops of methyl orange indicator. If the solution is alkaline, neutralize with nit
12、ric acid. Add3mL of nitric acid solution(3.1) in excess. Introduce the silver and mercury sulphate electrodes connected to the pH meter(4.1) and, while stirring, titrate with the silver nitrate solution. Plot a graph of millivolts or pH scale units as ordinates against millilitres of0.100mol/L silve
13、r nitrate solution(3.2). Read off the volume, T, in millilitres corresponding to the steepest part of the graph. 6 Expression of results The chloride content, expressed as a percentage by mass of sodium chloride (NaCl), is given by the following expression: 7 Test report The test report shall includ
14、e the following information: a) a reference to this BritishStandard, i.e.BS3762-3.16; b) the results and the method of expression used; c) the test conditions. where T is the volume of silver nitrate solution; c is the actual concentration of the silver nitrate solution(3.2) (in mol/L); m is the mas
15、s of the test portion (in g).2 blankBS3762-3.16:1985 BSI 12-1999 Publication referred to BS3978, Water for laboratory use. BS3762-3.16: 1985 BSI 389 Chiswick High Road London W4 4AL BSIBritishStandardsInstitution BSI is the independent national body responsible for preparing BritishStandards. It pre
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