1、BRITISH STANDARD BS 6829-2.3: 1989 ISO 6121:1988 Analysis of surface active agents (raw materials) Part 2: Alkane sulphonates Section 2.3 Method for determination of alkane monosulphonates content ISO title: Surface active agents Technical alkane sulfonates Determination of alkane monosulfonates con
2、tent by direct two-phase titration UDC 661.185.1:543.2112BS6829-2.3:1989 This British Standard, having been prepared under the directionof the Chemicals Standards Committee, was published under the authorityofthe Board of BSI andcomes intoeffect on 31 March 1989 BSI 12-1999 The following BSI referen
3、ces relate to the work on this standard: Committee reference CIC/34 Draft for comment 77/54031 DC ISBN 0 580 17131 0 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, upo
4、n which 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 Dete
5、rgent Industry Association Society of Dyers and Colourists Amendments issued since publication Amd. No. Date of issue CommentsBS6829-2.3:1989 BSI 12-1999 i Contents Page Committees responsible Inside front cover National foreword ii Introduction 1 1 Scope 1 2 Normative references 1 3 Definition 1 4
6、Principle 1 5 Reagents 1 6 Apparatus 3 7 Sampling 3 8 Procedure 3 9 Expression of results 3 10 Test report 3 Publications referred to Inside back coverBS6829-2.3:1989 ii BSI 12-1999 National foreword This Section of BS 6829 has been prepared under the direction of the Chemicals Standards Committee.
7、It is identical with IS06121:1988 “Surface active agents Technical alkane sulfonates Determination of alkane monosulphonates content by direct two-phase titration”, published by the International Organization for Standardization (ISO). Terminology and conventions. The text of the International Stand
8、ard 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 following. The comma has been used as a decimal marker. In British Standard
9、 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 BritishStandards it is current practice to use the symbol “L”. In British Standards it is current practice to use the spelling “sulphur”, etc.
10、, 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 for ISO385-1:1984 and ISO648:1977 are BS846:1985 “Specification for burettes” and BS1583:1986 “Specification for one-mark
11、pipettes”, respectively. The Technical Committee has reviewed the provisions of these two International Standards and, as the relevant requirements are identical with those of the related British Standards, has decided that they are acceptable for the purposes of this standard. As the reference to I
12、SO893 in the “Introduction” is supplied for information only, the lack of a corresponding British Standard does not affect the validity of this Section of BS6829. Additional information. With reference to clause5, water complying with grade3 of BS3978 “Specification for water for laboratory use” is
13、suitable. 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 1042:1983 BS 1792:1982 Specification for one-mark volumetric flasks (Identical) ISO 2271:1972 BS 3762 Analysi
14、s of formulated detergents Part 3 Quantitative test methods Section 3.1:1983 Method for determination of anionic-active matter content (Identical) ISO 6845:1982 BS 6829 Analysis of surface active agents (raw materials) Part 2 Alkane sulphonates Section 2.2:1987 Method for determination of mean relat
15、ive molecular mass of alkane monosulphonates (Identical)BS6829-2.3:1989 BSI 12-1999 iii 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 indicate that the method of test used is in accordance
16、with BS6829-2.3. 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 Standard does not of itself confer immunity from legal obligations. Summary of pages This do
17、cument comprises a front cover, an inside front cover, pagesi toiv, pages1to4, 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.iv blankBS6829-2
18、.3:1989 BSI 12-1999 1 Introduction The analytical method based on selective solvent extraction which has been applied successfully for the analysis of technical sodium alkane sulfonates in ISO893 leads to only approximate results during the analytical examination of the products of sulfochlorination
19、 and sulfoxidation of paraffins, owing to the presence of alkane disulfonates, in addition to alkane monosulfonates, formed during the synthesis. However, because of the different properties and applications of mixtures with different relative proportions of mono- and disulfonates, the knowledge of
20、the contents of such mixtures is of paramount importance. Therefore, it seemed advisable to establish this method to allow the determination specifically of the alkane monosulfonates content. The method is applicable to all synthetic alkane sulfonates and minimizes interference due to disulfonates.
21、1 Scope This International Standard specifies a method for the determination of the alkane monosulfonates content of technical alkane sulfonates containing small quantities of paraffins. It is applicable to all alkali metal salts of the products of sulfochlorination and sulfoxidation of paraffins. 2
22、 Normative references The following standards contain provisions which, through reference in this text, constitute provisions of this InternationalStandard. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this I
23、nternationalStandard are encouraged to investigate the possibility of applying the most recent editions of the standards listed below. Members of IEC and ISO maintain registers of currently valid InternationalStandards. ISO 385-1:1984, Laboratory glassware Burettes Part 1: General requirements. ISO
24、607:1980, Surface active agents and detergents Methods of sample division. ISO 648:1977, Laboratory glassware One-mark pipettes. ISO 1042:1983, Laboratory glassware One-mark volumetric flasks. ISO 2271:1972, Surface active agents Detergents Determination of anionic-active matter (Direct two-phase ti
25、tration procedure). ISO 6845:1982, Surface active agents Technical alkane sulfonates Determination of mean relative molecular mass of alkane monosulfonates. 3 Definition For the purpose of this International Standard, the following definition applies: alkane monosulfonate alkali metal salt of the mo
26、nosulfonic acids present in the technical products of sulfochlorination and sulfoxidation of pure straight-chain paraffins of which the chain consists of between12 and20 carbon atoms 4 Principle Determination of alkane monosulfonates content ina medium consisting of an aqueous phase and a chloroform
27、 phase, in the presence of sodium sulfate,by titration against a standard volumetric cationic-active solution (benzethonium chloride), in the presence of an indicator consisting of a mixture of a cationic dye (dimidium bromide) and an anionic dye (acid blue1). NOTEA description of the chemical proce
28、ss is given in ISO2271. 5 Reagents During the analysis, use only reagents of recognized analytical grade and only distilled water or water of equivalent purity. 5.1 Chloroform, 20 1,48g/ml, distilling between59,5 and61,5 C. 5.2 Sodium sulfate, anhydrous,200g/l solution. 5.3 Benzethonium chloride 1)
29、, standard volumetric solution, c(C 27 H 42 ClNO 2 )=0,004mol/l. Benzyl dimethyl-2-2-4(1,1,3,3- tetramethylbutyl)phenoxyethoxyethyl ammonium chloride, monohydrate: (CH 3 ) 3 -C-CH 2 -C-(CH 3 ) 2 -C 6 H 4 OCH 2 -CH 2 OCH 2 - CH 2 -N-(CH 3 ) 2 -CH 2 -C 6 H 5 + Cl H 2 O 5.3.1 Preparation of the solutio
30、n Weigh, to the nearest 0,001g, between1,75 and1,85g of benzethonium chloride and dissolve in water. 1) Hyamine 1622 is an example of a suitable product available commercially. This information is given for the convenience of users of this InternationalStandard and does not constitute an endorsement
31、 by ISO of this product.BS6829-2.3:1989 2 BSI 12-1999 Transfer the solution quantitatively to a1000ml one-mark volumetric flask fitted with a ground glass stopper, and make up to the mark with water. NOTEIn order to prepare a0,004mol/l solution, dry the benzethonium chloride at105 C, allow to cool i
32、n a desiccator, weigh1,792g to the nearest0,001g, dissolve in water and dilute to1000ml. 5.3.2 Standardization of the solution By means of a pipette, transfer25ml of a standard volumetric sodium lauryl sulfate solution, c(C 12 H 25 NaO 4 S)=0,004mol/l, to a bottle or measuring cylinder of100ml capac
33、ity, and add10ml of water,15ml of chloroform (5.1) and10ml of the mixed indicator solution (5.4). Titrate against the benzethonium chloride solution(5.3); stopper the bottle or measuring cylinder after each addition and shake well. The lower layer will be coloured pink. Continue the titration, with
34、repeated vigorous shaking. As the end point approaches, the emulsion formed during shaking tends to break easily. Continue the titration drop by drop, shaking after each addition of titrant, until the end point is reached. This is at the moment when the pink colour is completely discharged from the
35、chloroform layer, which becomes a faint greyish blue. 5.3.3 Calculation of the concentration The exact concentration, c, of the benzethonium chloride solution, expressed in moles of C 27 H 42 ClNO 2per litre, is given by the formula where c 0 is the exact concentration, in moles of C 12 H 25 NaO 4 S
36、 per litre, of the sodium lauryl sulfate solution used for the titration in5.3.2; V 0 is the volume, in millilitres, of the benzethonium chloride solution used for the titration in5.3.2. 5.4 Mixed indicator solution 2) 5.4.1 Stock solution This solution shall be prepared from acid blue1 and dimidium
37、 bromide. 5.4.1.1 Acid blue 1 3)(Colour Index 42045) (disodium-4,4 -dinitrilodiethyltriphenylmethane- 2,4-disulfonate): 5.4.1.2 Dimidium bromide (3,8-diamino-5-methyl-6- phenyl-phenanthridinium bromide): 5.4.1.3 Preparation of the stock solution Weigh, to the nearest0,001g,0,5g 0,005g of dimidium br
38、omide (5.4.1.2) into a50ml beaker, and0,25g 0,005g of acid blue1 (5.4.1.1) into a second50ml beaker. Add between 20 and 30ml of hot 10% (V/V) ethanol to each beaker. Stir until dissolved and transfer the solutions to a250ml one-mark volumetric flask. Rinse the beakers into the volumetric flask with
39、the ethanol and dilute to the mark with the ethanol. 5.4.2 Acid solution Add 200ml of water to20ml of the stock solution(5.4.1) in a500ml one-mark volumetric flask. Add20ml of a sulfuric acid solution (245g/l), mix and dilute to the mark with water. Store in the dark. 2) This mixed indicator is avai
40、lable commercially in the form of a basic solution, which should be acidified and diluted before use. c 0 25 V 0 - 3) Acid blue 1, VS blue and disulfine blue VN150 are examples of suitable products available commercially. This information is given for the convenience of users of this International S
41、tandard and does not constitute an endorsement by ISO of these products.BS6829-2.3:1989 BSI 12-1999 3 6 Apparatus Ordinary laboratory apparatus and: 6.1 One-mark volumetric flask, 250ml capacity, complying with the requirements of ISO1042. 6.2 Measuring cylinder or flask, 100ml capacity, with ground
42、 glass stopper. 6.3 One-mark pipettes, 20ml capacity, complying with the requirements of class A of ISO648. 6.4 Burette, 25ml capacity, complying with the requirements of class A of ISO385-1. 7 Sampling The laboratory sample of surface active agent shall be prepared and stored according to the instr
43、uctions given inISO607. 8 Procedure WARNING Comply with safety regulations relating to the handling of toxic solvents. 8.1 Test portion Weigh, to the nearest 0,001g, into a 150ml beaker, an amount of the laboratory sample which contains about0,4 to0,5g of alkane monosulfonate. 8.2 Determination Diss
44、olve the test portion (8.1) in50ml of water and transfer the solution quantitatively to the250ml one-mark volumetric flask (6.1). Add the washing solutions, and dilute to the mark with water. Mix throughly and then, by means of one of the pipettes (6.3), transfer20,0ml of this solution to the measur
45、ing cylinder or flask (6.2). Add successively, by means of measuring cylinders,10ml of the sodium sulfate solution(5.2),10ml of the mixed indicator solution(5.4), and15ml of chloroform (5.1). Stopper the measuring cylinder or flask and shake well. Titrate with the benzethonium chloride solution(5.3)
46、 contained in the burette (6.4), at first by successive additions of2 to3ml. After each addition stopper the measuring cylinder or flask and shake well. The lower layer of chloroform will be coloured pink. Continue the titration. As the end point approaches, the emulsion formed during shaking tends
47、to break easily and the coloration of the chloroform layer becomes fainter. From this point continue the titration by additions of0,5ml, then drop by drop, shaking after each addition of titrant, until the end point is reached. This is at the moment when the pink colour is completely discharged from
48、 the chloroform layer, which turns a faint greyish blue. 9 Expression of results 9.1 Calculation The alkane monosulfonates content, expressed as a percentage by mass, is given by the formula where V is the volume, in millilitres, of the benzethonium chloride solution (5.3) used for the titration of
49、a20ml aliquot portion of alkane sulfonate solution; c is the exact concentration, in moles of C 27 H 42 ClNO 2per litre, of the benzethonium chloride solution (5.3); M r is the relative molecular mass of the alkane monosulfonate, determined according to ISO6845; m 0 is the mass, in grams, of the test portion(8.1). 9.2 Precision Comparative analyses of a sample in the form of a homogeneous aqueous solution containing about25% (m/m) of total soluble matter comprising alkane mono-, di- and polysulfonates in the form o
