ISO INTERNATIONAL STANDARD 11021 First edition 1999-10-01 Essential oils Determination of water content Karl Fischer method Huiles essentielles Détermination de la teneur en eau Méthode de Karl Fischer ISO Referencenumber ISO 11021:1999(E) se with itted without license from IHS Not for Resale ISO 11021:1999(E) Foreword IsO (the International Organization for Standardization) is a worldwide federation of national standards bodies (isO liaison with ISO, , also take part in the work. isO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. International Standards are drafted in accordance with the rules given in the ISO/lEC Directives, Part 3 International Standard ISO 11021 was prepared by Technical Committee ISO/TC 54, Essential oils @ISO1999 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the publisher. International Organization for Standardization Case postale 56 CH-1211 Geneve 20 · Switzerland Internet [email protected] Printed in Switzerland Not for Resale ISO 11021:1999(E) INTERNATIONALSTANDARD ISO Essential oils Determination of water content - Karl Fischer method 1 Scope This International Standard specifies a method for the determination of the water content of essential oils by the Karl Fischer method. 2 Normative reference The following normative document contains provisions which, through reference in this text, constitute provisions of this International Standard. For dated references, subsequent amendments to, or revisions of, this publication do possibility of applying the most recent edition of the normative document indicated below. For undated references: the latest edition of the normative document referred to applies. Members of isO and IEC maintain registers of currently valid International Standards. ISO 760, Determination of water content Karl Fischer method (General method) 3 Terms and definitions For the purposes of this International Standard, the following term and definition apply. 3.1 watercontent this International Standard NOTE Water content is expressed as a mass fraction in percent [formerly designated as % (m/m)]. 4 Principle of the reaction is obtained by an electrometric method. 5 Reactions During the determination of water according to the Karl Fischer method, the water present in the sample reacts, in the presence of an amine and an alcohol, with iodine and sulfur dioxide: H2O + I2 + SO2 + ROH + 3RnNH3-n → 2RnNH3-nHI + RnNH3-nHSO4R where R is an alkyl or alkoxyl group. The endpoint of the reaction is obtained electrometrically by a surplus of iodine. Not for Resale