1、BRITISH STANDARDBS EN 14670:2005Surface active agents Sodium dodecyl sulfate Analytical methodThe European Standard EN 14670:2005 has the status of a British StandardICS 71.100.40g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g
2、54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58BS EN 14670:2005This British Standard was published under the authority of the Standards Policy and Strategy Committee on 5 September 2005 BSI 5 September 2005ISBN 0 580 46386 9National forewordThis British Standard is th
3、e official English language version of EN 14670:2005.The UK participation in its preparation was entrusted to Technical Committee CII/34, Methods of test for surface active agents, which has the responsibility to:A list of organizations represented on this committee can be obtained on request to its
4、 secretary.Cross-referencesThe British Standards which implement international or European publications referred to in this document may be found in the BSI Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Search” facility of the BSI Electronic Ca
5、talogue or of British Standards Online.This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application.Compliance with a British Standard does not of itself confer immunity from legal obligations. aid enquirers to understand
6、the text; present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep UK interests informed; monitor related international and European developments and promulgate them in the UK.Summary of pagesThis document comprises a front co
7、ver, an inside front cover, the EN title page, pages 2 to 10, an inside back cover and a back cover.The BSI copyright notice displayed in this document indicates when the document was last issued.Amendments issued since publicationAmd. No. Date CommentsEUROPEAN STANDARDNORME EUROPENNEEUROPISCHE NORM
8、EN 14670June 2005ICS 71.100.40English versionSurface active agents - Sodium dodecyl sulfate - AnalyticalmethodAgents de surface - Dodcylsulfate de sodium - MthodedanalyseGrenzflchenaktive Stoffe - Natriumdodecyulsulfat -AnalysenverfahrenThis European Standard was approved by CEN on 19 May 2005.CEN m
9、embers are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this EuropeanStandard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such nationalstandards may be obtained on applicat
10、ion to the Central Secretariat or to any CEN member.This European Standard exists in three official versions (English, French, German). A version in any other language made by translationunder the responsibility of a CEN member into its own language and notified to the Central Secretariat has the sa
11、me status as the officialversions.CEN members are the national standards bodies of Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France,Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia,Slov
12、enia, Spain, Sweden, Switzerland and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMIT EUROPEN DE NORMALISATIONEUROPISCHES KOMITEE FR NORMUNGManagement Centre: rue de Stassart, 36 B-1050 Brussels 2005 CEN All rights of exploitation in any form and by any means reservedworldwide for CEN nati
13、onal Members.Ref. No. EN 14670:2005: EEN 14670:2005 (E) 2 Contents Page Foreword 3 1 Scope .4 2 Normative references .4 3 Principle.4 4 Reagents4 5 Apparatus 5 6 Sampling and preparation of the sample 5 7 Procedure 5 8 Expression of results6 9 Precision7 10 Test report .7 Annex A (informative) Typic
14、al gas chromatogram.8 Annex B (informative) Results of inter-laboratory test 9 Bibliography.10 EN 14670:2005 (E) 3 Foreword This European Standard (EN 14670:2005) has been prepared by Technical Committee CEN/TC 276 “Surface active agents”, the secretariat of which is held by AFNOR. This European Sta
15、ndard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by December 2005, and conflicting national standards shall be withdrawn at the latest by December 2005. According to the CEN/CENELEC Internal Regulations, the national
16、standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portuga
17、l, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EN 14670:2005 (E) 4 1 Scope This European Standard specifies a method for the determination of the active content and molar mass of sodium dodecyl sulphate used as original titre for the titre determination of standard solutions f
18、or surface active agents titration. NOTE These are used in the mixed indicator two-phase titration (e. g. ISO 2271) and in the potentiometric titration using a surface active agent sensitive electrode (e.g. EN 14480). 2 Normative references The following referenced documents are indispensable for th
19、e application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. EN 13267, Surface active agents Determination of water content Karl Fischer method. EN ISO 3696, Water for a
20、nalytical laboratory use Specification and test methods (ISO 3696:1987). ISO 607, Surface active agents and detergents Methods of sample division. ISO 894, Surface active agents Technical sodium primary alkylsulphates Methods of analysis. ISO 6844, Surface active agents Determination of mineral sulf
21、ate content Titrimetric method. 3 Principle The water content, the sodium sulphate content and the extractable matter content by light petroleum of the test sample are determined according to the methods respectively described in EN ISO 3696, ISO 894 and ISO 9844 and the active content is calculated
22、 by subtracting the water content, the sodium sulphate content and the content of extractable matter by light petroleum from 100 %. For calculating the average molar mass of the sodium dodecyl sulphate the fatty alcohols C10to C14released after acidic hydrolysis are isolated and the C-chain distribu
23、tion is determined by gas chromatography. 4 Reagents During the analysis, unless otherwise specified, use only reagents of recognized analytical grade which have been checked in advance as not interfering with the analytical results and water complying with grade 3 as defined in EN ISO 3696 and in p
24、articular use. a) for the determination of the water content, the reagents specified in EN 13267; b) for the determination of the sodium sulphate content, the reagents specified in ISO 6844 (or prEN 14880). ; c) for the determination of extractable matter content by light petroleum, the reagents spe
25、cified in ISO 894. EN 14670:2005 (E) 5 5 Apparatus Normal laboratory apparatus and the following: 5.1 Gas chromatograph, suitable for work with a fused silica capillary column and equipped with a flame ionization detector (FID). 5.2 Capillary column, capable of the separation characteristics shown i
26、n Figure A.1. NOTE A 30 m x 0.32 mm ID, fused silica capillary column (film thickness 0,25 m) with 5 % phenyl-, 95 % methyl polysiloxane stationary phase is advisable. 6 Sampling and preparation of the sample The laboratory sample shall be prepared and stored in accordance with ISO 607. 7 Procedure
27、7.1 Determination of water content Determine the water content in accordance with EN 13267. NOTE Usually the water content is 1 % (m/m). 7.2 Determination of the sodium sulphate content Determine the sodium sulphate content in accordance with ISO 6844 (dithizone method). NOTE Usually the sodium sulp
28、hate content is 0,1 % (m/m). 7.3 Determination of the extractable matter content by light petroleum Determine the extractable matter content by light petroleum in accordance with ISO 894. NOTE 1 Usually the content is 0,2 % (m/m). NOTE 2 For the determination of the unsulphated matter, EN 13273 may
29、also be applied if an appropriate calibrant (C12-alcohol) is available. 7.4 Determination of the average molar mass of sodium dodecyl sulfate Extract the light petroleum soluble matter in accordance with ISO 894 from the neutralized aqueous ethanolic solution of the test sample. After acid hydrolysi
30、s of the alkyl sulphate remaining in the aqueous ethanolic phase, extract the released fatty alcohol with diethyl ether in accordance with ISO 894. Evaporate the dried diethyl ether extract to a volume of approximately 20 ml. Determine the C-chain distribution of the fatty alcohol using gas chromato
31、graphy with the given parameters. The peak assignment can be done with a fatty alcohol kit serving as reference. At least the quality of separation shown in Figure A.1 shall be achieved. EN 14670:2005 (E) 6 8 Expression of results 8.1 Calculation of the active content The active content, w, expresse
32、d as grams per 100 g, is calculated according to equation (1): mewwww =422SONa0H100 (1) where 0H2w is the water content according to 7.1, in grams per 100 g; 42SONaw is the sodium sulphate content according to 7.2, in grams per 100 g; mew is the content of matter extractable by light petroleum accor
33、ding to 7.3, in grams per 100 g. 8.2 Calculation of the average molar mass The average molar mass, M, expressed as grams per mole, is calculated according to equation (2): () () 11911212 +=nAnAMnn(2) where n is the C-number of the fatty alcohol; Anis the relative area for the fatty alcohol n. EN 146
34、70:2005 (E) 7 9 Precision 9.1 General Despite the sometimes considerable statistical variations during the analysis of minor constituents, the subtraction method offers the most reliable results for the analysis of the active content. As the contents of the minor constituents are generally 0,1 % (m/
35、m) for sodium sulphate and unsulphated matter and 1 % (m/m) for water, high variation coefficients have only low effect on the final result. The same applies to the high variation coefficient for the C10and C14fatty alcohol analysis. 9.2 Repeatability limit The absolute difference between two indepe
36、ndent single test results, obtained using the same method on identical test material in the same laboratory by the same operator using the same equipment within a short interval of time, will not exceed the repeatability limit, r, in more than 5 % of cases. Precision data are given in Annex B. 9.3 R
37、eproducibility limit The absolute difference between two independent single test results, obtained using the same method on identical test material in different laboratories by different operators using different equipment, will not exceed the reproducibility limit, R, in more than 5 % of cases. Pre
38、cision data are given in Annex B. 10 Test report The test report shall include the following information: a) all information necessary for the complete identification of the sample; b) method used (a reference to this European Standard); c) test results; d) details of any operations not specified in
39、 this document or in the European standards to which reference is made, and any operations regarded as optional, as well as any incidents likely to have affected the results. EN 14670:2005 (E) 8 Annex A (informative) Typical gas chromatogram Key 1 Retention time in minutes 2 Response, in millivolts
40、Figure A.1 - Typical gas chromatogram The following gas chromatography conditions have been found to be suitable: Column : A 30 m x 0.32 mm ID, fused silica capillary column (film thickness 0,25 m) with 5 % phenyl-, 95 % methyl polysiloxane stationary phase is advisable. Carrier gas: helium Column H
41、ead-pressure: 115 kPa Gas flow: 3 ml/min Split ratio: 1:50 Sample quantity: 1 l of a 10 % solution Temperature program: 50 C for 1 min, then up to 120 C at 15 C/min, then up to 330 C at 60 C/min Injector: 280 C Detector: 350 C Evaluation : normalisation of the peak area ratio to 100 % (GC area-perce
42、nt) EN 14670:2005 (E) 9 Annex B (informative) Results of inter-laboratory test The inter-laboratory test was carried out in 1992 by GAT (Gemeinschaftsausschuss fr die Analytik von Tensiden). The results of the inter-laboratory test were evaluated in accordance with ISO 5725-2. Table B.1 Results of i
43、nter-laboratory test (active content) Designation Water Na2SO4Matter extractable by light petroleum Active contentMethod EN 13267 ISO 6844 ISO 894 Number of laboratories participating 10 10 10 10 Number of laboratories not eliminated 9 10 9 8 Number of individual test results of all laboratories 20
44、20 20 20 Mean value, m, in g/100 g 0,88 0,03 0,09 99,0 Repeatability standard deviation, Sr, in g/100 g 0,02 0,01 0,02 0,04 Repeatability, r = (Sr 2,8), in g/100 g 0,06 0,03 0,06 0,12 Reproducibility standard deviation, SR, in g/100 g 0,12 0,02 0,05 0,13 Reproducibility, R = (SR 2,8), in g/100 g 0,3
45、3 0,05 0,15 0,36 Repeatability coefficient of variation in % 2,3 33,3 22,2 0,04 Reproducibility coefficient of variation in % 13,6 66,6 55,6 0,13 Table B.2 Results of inter-laboratory test (Gas chromatography data for molar mass determination) Designation C10-OH C12-OH C14-OH Number of laboratories
46、participating 7 7 7 Number of laboratories not eliminated 5 7 6 Number of individual test results of all laboratories 10 14 14 Mean value, m, in g/100 g 0,2 99,4 0,6 Repeatability standard deviation, Sr, in g/100 g 0,03 0,07 0,07 Repeatability, r = (Sr 2,8), in g/100 g 0,09 0,20 0,20 Reproducibility
47、 standard deviation, SR, in g/100 g 0,07 0,25 0,09 Reproducibility, R = (SR 2,8), in g/100 g 0,21 0,71 0,26 Repeatability coefficient of variation in % 59,0 0,2 34,9 Reproducibility coefficient of variation in % 138,4 0,7 44,7 The average molar mass of the sodium dodecyl sulfate used in the inter-la
48、boratory test is calculated according to the following equation based on the above results: ()11911140060129940100020212140060129940100020 += ,M 4288,=M g/mol EN 14670:2005 (E) 10 Bibliography 1 EN 13273, Surface active agents Determination of the content of non-ionic substances in anionic surface a
49、ctive agents by high performance liquid chromatography (HPLC). 2 EN 14480, Surface active agents - Determination of anionic surface active agents - Potentiometric two-phase titration method. 3 prEN 14880, Surface active agents - Determination of inorganic sulphate content in anionic surface active agents - Potentiometric lead selective electrode titration method 4 ISO 2271, Surface active agents - Detergents - Determination of anionic-active matter by manual or mechanical direct two-pha
