ISO INTERNATIONAL STANDARD 20596-2 First edition 2021-01 Water quality - Determination of cyclic volatile methylsiloxanes in water. Part 2: Method using liquid-liquid extraction with gas chromatography-mass spectrometry (GC-MS) Qualitéde I'eau-Détermination deméthylsiloxanescycliques volatilesdansI'eau- Partie2:Methodeparextractionliquide-liquideavec chromatographieenphasegazeuse-spectrometriedemasse (CG-sM) Reference number IS0 20596-2:2021(E) ISO @IS0 2021 Copyright Intern national Organization for Standardizatior IS020596-2:2021(E) COPYRIGHTPROTECTEDDOCUMENT ISO2021 All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting below or Iso's member body in the country of the requester. ISo copyright office CP 40i:Ch.de Blandonnet 8 CH-1214 Vernier,Geneva Phone: +41 22 749 01 11 Email: [email protected] Website: www.iso.org Published in Switzerland Copyright HEeretralibgriatrbsStarndardzafion IS0 2021-All rights reserved IS020596-2:2021(E) Contents Page Foreword .iv Introduction .. 1 Scope. ..1 2 Normativereferences ..1 3 Terms and definitions .2 4 Principle .2 4.1 Principleof preservationand extraction .2 5 Interferences .2 5.1 Interferences with sampling and processing .2 5.2 Interferences with GC-MS .2 5.3 Interferencesdetermination .3 6 Reagents. .3 7 .5 Apparatus 8 Method detection limits .6 9 Quality control ..6 10 Sampling and storage .6 10.1 Sampling preparation .6 10.2 Sample collection .6 11 Extraction and analysis. ..7 11.1 Extraction. .7 11.2 GC conditions and operation .7 12 Calibration .7 12.1 General requirements .7 12.2 Calibration calculations ..8 12.3 Concentration calculations .8 12.4 Calculation of results 12.5 Treatment of results lying outsidethe calibrationrange .9 13 Expression of results .10 14 Testreport .10 AnnexA (informative)GC-MS conditions ..11 Annex B (informative) Method detection limit and limit of quantification ..13 Annex C (informative) Examplequality control samples .14 Annex D (informative) Performance data .15 Bibliography .16 iii IS020596-2:2021(E) Foreword Iso(theInternational Organization for Standardization)is a worldwidefederationofnational standards bodies (Iso member bodies). The work of preparing International Standards is normally carried out through Iso technical committees.Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations,governmental and non-governmental, in liaison with Iso,also take part in the work. Iso collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. The procedures used to develop this document and those intended for its further maintenance are described in the ISo/lEC Directives, Part 1. In particular, the different approval criteria needed for the differenttypes of Iso documents should be noted.This documentwas drafted inaccordance with the editorial rules of the ISo/IEC Directives, Part 2 (see www.iso.org/directives). Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. IsO shall not be held responsible for identifying any or all such patent rights. Details of anypatentrights identified during the development of the document will be in the Introduction and/or on the Iso list of patent declarations received (see www.iso.org/patents). Any trade nameused in this document is information given for the convenience of users and does not constitute an endorsement. For an explanation of the voluntary nature of standards, the meaning of Iso specific terms and expressions related to conformity assessment, as well as information about Iso's adherence to the iso/foreword .html. This document was prepared by Technical Comm