1、BRITISH STANDARD BS 6829-1.2: 1988 ISO 4314:1977 Incorporating Amendment No. 1 Analysis of surface active agents (rawmaterials) Part 1: General methods Section 1.2 Method for determination of free alkalinity or free acidity ISO title: Surface active agents Determination of free alkalinity or free ac
2、idity Titrimetric method UDC 661.185.1:543.2 112BS 6829-1.2:1988 This British Standard, having been prepared under the directionof the Chemicals Standards Committee, was published under the authority ofthe Board of BSI and comes into effect on 31August1988 BSI 01-2000 The following BSI references re
3、late to the work on this standard: Committee reference CIC/34 Draft for comment 87/53366 DC ISBN 0 580 16684 8 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 whic
4、h the following bodies were represented: Chemical Industries Association Consumer Policy Committee of BSI Department of the Environment Department of Trade and Industry (Laboratory of the Government Chemist) London Regional Transport Ministry of Defence Royal Society of Chemistry Soap and Detergent
5、Industry Association Society of Dyers and Colourists Society of Occupational Medicine Textile Institute Textile Research Council Amendments issued since publication Amd. No. Date of issue Comments 7848 September 1993 Indicated by a sideline in the marginBS 6829-1.2:1988 BSI 01-2000 i Contents Page C
6、ommittees responsible Inside front cover National foreword iii 1 Scope and field of application 1 2 Reference 1 3 Definition 1 4 Principle 1 5 Reagents 1 6 Apparatus 1 7 Sampling 1 8 Procedure 1 9 Expression of results 1 10 Test report 1 Publications referred to Inside back coverBS 6829-1.2:1988 ii
7、BSI 01-2000 National foreword This Section of BS6829 has been prepared under the direction of the Chemicals Standards Committee. It is identical with ISO4314:1977 “Surface active agents Determination of free alkalinity or free acidity Titrimetric method”, published by the International Organization
8、for Standardization (ISO). 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 es
9、pecially to the following. 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). In British Standards it is current practice to use th
10、e symbol “L”. Wherever the words “International Standard” appear, referring to this standard, they should be read as “Section of BS 6829”. The footnote to clause2 should be deleted. With reference to6.2, ISO385 has been revised as ISO385-1:1984, ISO385-2:1984 and ISO385-3:1984, the relevant requirem
11、ents of which are technically equivalent to those in BS846:1985 “Specification for burettes”. Additional information. With reference to clause5, water complying with grade3 of BS3978 “Specification for water for laboratory use” is suitable. With reference to5.1 the ethanol may be replaced by industr
12、ial methylated spirits complying with the requirements of BS3591, or such spirits diluted as required. It should be noted that the use of industrial methylated spirits is governed by The Methylated Spirits Regulations, 1983 (S.I. 1983 No. 252). It is not permissible to use duty-free ethanol, receive
13、d under the provisions of the Alcoholic Liquors Duties Act1972, Section10, for purposes for which industrial methylated spirits is an acceptable alternative. With reference to5.2, the concentration of the potassium hydroxide standard volumetric solution, expressed as an amount-of-substance concentra
14、tion, is c (KOH)=0.1mol/L. With reference to5.3, the general practice in the UKistouse only standard volumetric hydrochloric acid solution, the concentration ofwhich, expressed as an amount-of-substance concentration, is c (HCl) =0.1mol/L. The UK will propose the deletion of sulphuric acid solution
15、at the next review of ISO4314. In the definition of T in clause9, “normality” should be read as “amount-of-substance concentration (mol/L)”. This Section describes a method of test only and should not be used or quoted as a specification defining limits of purity. Reference to this Section should in
16、dicate that the method of test used is in accordance with BS6829-1.2. Cross-references International Standard Corresponding British Standard ISO 607:1980 BS 3762 Analysis of formulated detergents Part 1:1983 Methods of sample division (Identical) ISO 1773:1976 BS 2734:1984 Specification for boiling
17、flasks (narrow-necked), conical, flat bottom and round bottom (Identical)BS6829-1.2:1988 BSI 01-2000 iii A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Stan
18、dard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pages i to iv, pages1and 2, an inside back cover and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporat
19、ed. This will be indicated in the amendment table on the inside front cover.iv blankBS6829-1.2:1988 BSI 01-2000 1 1 Scope and field of application This International Standard specifies a titrimetric method for the determination of free alkalinity or free acidity of surface active agents. This method
20、 is applicable only if so indicated in the specific standard for each product. 2 Reference ISO 607, Surface active agents Detergents Methods of sample division 1) . 3 Definition free alkalinity or free acidity the alkalinity or acidity determined using phenolphthalein as indicator, expressed as the
21、“alkali value” or the “acid value” as the case may be, i.e.in milligrams of potassium hydroxide present in1g of the product or required to neutralize1g of the product 4 Principle Titration of an ethanolic or propanolic solution of the product with a standard volumetric potassium hydroxide or hydroch
22、loric acid or sulphuric acid solution whichever is appropriate, in the presence of phenolphthalein 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 Ethanol, 95% (V/V), or propan-2-ol, 50% (V/V),
23、 neutralized solution. Reflux the selected solution gently for5min to eliminate carbon dioxide. Cool to ambient temperature and neutralize with the potassium hydroxide solution (5.2) in the presence of the phenolphthalein solution (4 drops per200ml), untilthe indicator just turns pink. 5.2 Potassium
24、 hydroxide, 0,1N standard volumetricsolution. 5.3 Hydrochloric acid or sulphuric acid, 0,1 N standard volumetric solution. 5.4 Phenolphthalein, 10g/l solution in9,5% (V/V) ethanol. 6 Apparatus Ordinary laboratory apparatus, and in particular: 6.1 Conical flask, capacity250ml, complying with the requ
25、irements of ISO1773. 6.2 Burette, capacity25ml, complying with the requirements of class Aof ISO385. 7 Sampling The laboratory sample of the surface active agent shall be prepared and stored according to the instructions given in ISO607. 8 Procedure 8.1 Test portion Weigh, to the nearest0,001g, abou
26、t10g of the laboratory sample into the conical flask (6.1). 8.2 Determination Add100ml of the ethanol or the propan-2-ol (5.1) and shake to dissolve the test portion (8.1) completely. Add4 to5 drops of the phenolphthalein solution (5.4). If the solution remains colourless, titrate, using theburette
27、(6.2), with the potassium hydroxide solution (5.2). If the solution is pink, titrate in the same manner with either the hydrochloric acid or sulphuric acid solution (5.3). 9 Expression of results The alkali value (IB) or acid value (IA), expressed inmilligrams of potassium hydroxide per gram of prod
28、uct, is given by the formula where V is the volume, in millilitres, of the standard volumetric solution(5.2) or(5.3) used; T is the exact normality of the standard volumetric solution used; m is the mass, in grams, of the test portion. 10 Test report The test report shall include the following parti
29、culars: a) all information necessary for the complete identification of the sample; b) the reference to the method used; c) the results obtained and the form in which they are expressed; d) the test conditions; e) any operation not included in this International Standard or regarded as optional, as
30、well as any incidents which may have affected the results. 1) In preparation. (Revision of ISO/R607.) VT 561 , m -2 blankBS6829-1.2:1988 BSI 01-2000 Publications referred to See national foreword.BS 6829-1.2: 1988 ISO4314:1977 BSI 389 Chiswick High Road London W4 4AL BSIBritishStandardsInstitution B
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