1、BRITISH STANDARD BS 6829-1.1: 1987 ISO 6844:1983 Analysis of surface active agents (rawmaterials) Part 1: General methods Section 1.1 Method for determination ofmineral sulphate content ISO title: Surface active agents Determination of mineral sulfate content Titrimetric method UDC 661.185.1:543.2-1
2、12BS 6829-1.1:1987 This British Standard, having been prepared under the directionof the Chemicals Standards Committee, was published under the authority ofthe Board of BSI and comesintoeffect on 27February1987 BSI 12-1999 The following BSI references relate to the work on this standard: Committee r
3、eference CIC/34 Draft for comment 82/51684 DC ISBN 0 580 15815 2 Committees responsible for this British Standard The preparation of this British Standard was entrusted by the Chemicals Standards Committee (CIC/-) to Technical Committee CIC/34 upon which the following bodies were represented: Chemic
4、al Industries Association Consumer Standards Advisory Committee of BSI Department of the Environment Department of Trade and Industry (Laboratory of the Government Chemist) Fabric Care Research Association London Regional Transport Ministry of Defence Royal Society of Chemistry Soap and Detergent In
5、dustry Association Society of Dyers and Colourists Society of Occupational Medicine Textile Institute Amendments issued since publication Amd. No. Date of issue CommentsBS6829-1.1:1987 BSI 12-1999 i Contents Page Committees responsible Inside front cover National foreword ii 1 Scope 1 2 Field of app
6、lication 1 3 References 1 4 Principle 1 5 Reagents 1 6 Apparatus 1 7 Sampling 1 8 Procedure 1 9 Expression of results 2 10 Test report 2 Table 1 Mass of test portion 2 Table 2 Volume of aliquot portions 2 Table 3 Precision 2 Publications referred to Inside back coverBS 6829-1.1:1987 ii BSI 12-1999 N
7、ational foreword This Section of BS6829 has been prepared under the direction of the ChemicalsStandards Committee. It is identical with ISO6844:1983 “Surface active agents Determination of mineral sulfate content Titrimetric method”, published by the International Organization for Standardization (I
8、SO). Terminology and conventions. The text of the International Standard has been approved as suitable for publication as a British Standard without deviation. Some terminology and certain conventions are not identical with those used in British Standards; attention is drawn especially to the follow
9、ing. The comma has been used as a decimal marker. In British Standards it is current practice to use a full point on the baseline as the decimal marker. The symbol “l” has been used to denote litre (and in its submultiples). InBritishStandards it is current practice to use the symbol “L”. In British
10、 Standards it is current practice to use the spelling “sulphur”, etc., instead of “sulfur”, etc. Wherever the words “International Standard” appear, referring to this standard, they should be read as “Section of BS6829”. Related British Standards to ISO385-2:1984 1)and ISO648:1977 are BS846:1985 “Sp
11、ecification for burettes” and BS1583:1986 “Specification for one-mark pipettes”, respectively. Additional information. With reference to clause5, water complying with BS3978 “Water for laboratory use” is suitable. This Section describes a method of test only and should not be used or quoted as a spe
12、cification defining limits of purity. Reference to this Section should indicate that the method of test used is in accordance with BS6829-1.1. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct appli
13、cation. 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, pages i and ii, pages1 and 2, an inside back cover and a back cover. This standard has been updated (see copyright date
14、) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover. Cross-references International Standard Corresponding British Standard ISO607:1980 BS3762 Analysis of formulated detergents Part 1:1983 Methods of sample division (Identical) ISO835-2
15、:1981 BS700 Graduated pipettes Part 2:1982 Specification for pipettes for which no waiting time is specified (Identical) ISO1042:1983 BS1792:1982 Specification for one-mark volumetric flasks (Identical) 1) The footnote relating to ISO385-2, in clause3, is not now valid as the standard was published
16、in1984.BS6829-1.1:1987 BSI 12-1999 1 1 Scope This International Standard specifies a titrimetric method for the determination of the mineral sulfate content of surface active agents. 2 Field of application This International Standard applies to anionic surface active agents, containing sodium, ammon
17、ium and alkanolamine sulfates. It is not applicable to products containing other compounds such as phosphates or large amounts ofchloride, which also give a sparingly soluble lead salt under the conditions of the test, nor is it applicable in the presence of large amounts of salts of weak acids (for
18、 example, soaps or monoesters of sulfosuccinic acid) which prevent the correct adjustment of the pH. NOTIt is essential to conduct the determination at the apparent pH specified in note1 to8.2. At apparent pH values below4, the reaction is not stoichiometric. This International Standard is applicabl
19、e only if so indicated in the relevant International Standard for each product. 3 References ISO385-2, Laboratory glassware Burettes Part2: Burettes for which no waiting time is specified 2) . ISO607, Surface active agents and detergents Methods of sample division. ISO648, Laboratory glassware One-m
20、ark pipettes. ISO835-2, Laboratory glassware Graduated pipettes Part2: Pipettes for which no waiting time is specified. ISO1042, Laboratory glassware One-mark volumetric flasks. 4 Principle Titration of a buffered acetonic solution of a test portion with a standard volumetric lead(II) nitrate soluti
21、on in the presence of dithizone as indicator. 5 Reagents During the analysis, use only reagents of recognized analytical grade and only distilled water or water of equivalent purity. 5.1 Acetone 5.2 Nitric acid, solution c(HNO 3 ) . 1mol/l. 5.3 Sodium hydroxide,40g/l solution. 5.4 Lead(II) nitrate,
22、standard volumetric solution, cPb(NO 3 ) 2 =0,01mol/l. Dissolve3,312 0,005g of lead(II) nitrate in200ml of water. Transfer to a1000ml one-mark volumetric flask fitted with a ground glass stopper, dilute to the mark with water and mix thoroughly. 5.5 Ammonium dichloroacetate, buffer solution, pH1,5 t
23、o1,6, giving in acetonic medium,70 to85% (V/V), an apparent pH value of4,1 0,2. Add67ml of dichloroacetic acid to about250ml water and carefully neutralize with18% (m/m) ammonia solution (about80ml) to pH7 as indicated by a pH-meter or a precise indicator paper. Allow to cool, add a further33ml of d
24、ichloroacetic acid and dilute to600ml. 5.6 1,5-Diphenyl thiocarbazone (Dithizone) (C 6 H 5 NHNHCSN=NC 6 H 5 ),0,5g/l solution inacetone. Store in a dark bottle and discard after1 week. 6 Apparatus Ordinary laboratory apparatus and 6.1 Beaker, of capacity150ml. 6.2 One-mark volumetric flask, of capac
25、ity100ml, complying with the requirements of ISO1042. 6.3 Conical flask, of capacity250ml. 6.4 Pipettes, of capacities5 10 15 and20ml, complying with the requirements of ISO648. 6.5 Graduated pipette, of capacity1 or2ml, complying with the requirements of ISO835-2. 6.6 Burette, of capacity25ml, comp
26、lying with the requirements of class A of ISO385-2. 6.7 Graduated measuring cylinder, of capacity100ml. 7 Sampling The laboratory sample of the surface active agentshall be prepared and stored according totheinstructions given in ISO607. 8 Procedure 8.1 Test portion Depending on the expected sodium
27、sulfate content, weigh, to the nearest0,001g, the amount of laboratory sample given in Table 1, into the beaker(6.1). 2) At present at the stage of draft. (Revision, in part, of ISO/R385:1964.)BS 6829-1.1:1987 2 BSI 12-1999 Table 1 Mass of test portion 8.2 Determination Dissolve the test portion(8.1
28、) in about50ml of water by warming, if necessary, to not more than50 C. Transfer quantitatively to the one-mark volumetric flask(6.2), dilute to the mark with water and mix thoroughly. By means of one of pipettes(6.4), take an appropriate aliquot portion, depending on the expected sodium sulfate con
29、tent as given in Table 2. Table 2 Volume of aliquot portions Transfer the aliquot portion to the conical flask(6.3) and make up to20ml with water. Add1ml of dithizone solution(5.6). If the solution is green, add the sodium hydroxide solution(5.3) until the appearance of a red colour. Add the nitric
30、acid solution(5.2), drop by drop, until the appearance of a green colour and then add2,0ml of the ammonium dichloroacetate solution(5.5) and80ml of the acetone(5.1). Immediately after the addition of the acetone, titrate the buffered acetonic solution with the lead(II) nitrate solution(5.4) until a
31、brick-red colour that is stable for15s is obtained. NOTE 1The initial apparent pH value is4,1 0,2 and decreases considerably during the determination. NOTE 2At the end-point the acetone content shall be between70 and85% (V/V). 9 Expression of results 9.1 Method of calculation The mineral sulfate con
32、tent, expressed as a percentage by mass of sodium sulfate, is given by the formula where m 0 is the mass, in grams, of the test portion(8.1); V 0 is the volume, in millilitres, of the aliquot portion taken for the determination(8.2); V 1 is the volume, in millilitres, of the lead(II) nitrate solutio
33、n(5.4) used in the determination(8.2); c is the actual concentration, expressed in moles of Pb(NO 3 ) 2per litre, of the lead(II) nitrate solution(5.4); 0,142is the mass, in grams, of sodium sulfate corresponding to1,00ml of lead(II) nitrate solution, cPb(NO 3 ) 2 =1,000mol/l. 9.2 Precision Comparat
34、ive analyses, on samples of two ammonium laurylethersulfates containing respectively about0,15 and1,15% (m/m) of mineral sulfate carried out in seven laboratories, have given the statistical results given in Table 3. Table 3 Precision 10 Test report The test report shall include the following inform
35、ation: a) all information necessary for the complete identification of the sample; b) the reference of the method used (reference to this International Standard); c) the results and the method of expression used; d) the test conditions; e) any details not specified in this International Standard or
36、in ISO607 to which reference is made, or regarded as optional, as well as any incidents likely to have affected the results. Expected sodium sulfate content in sample Mass of test portion %(m/m) g 6 a 10 to 14 5 3 1 to 3 0,5 to 1,5 0,5 5,0 10,0 15,0 20,0 Mineral sulfate content Mean value 0,16% (m/m
37、) 1,10% (m/m) Standard deviation ofrepeatability, r 0,02 0,04 Standard deviation ofreproducibility, R 0,04 0,16BS6829-1.1:1987 BSI 12-1999 Publications referred to See national foreword.BS 6829-1.1: 1987 ISO 6844:1983 BSI 389 Chiswick High Road London W4 4AL BSIBritishStandardsInstitution BSI is the
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