ISO INTERNATIONAL 1279 STANDARD Third edition 1996-12-15 ANsl Internat Doc Sec Essential oils -- Determination of carbonyl value Potentiometric methods using hydroxylammonium chloride HuilesessentiellesDetermination deI'indicede carbonyle- Methodes potentiometriques au chlorure d'hydroxylammonium ISO Reference number ISO1279:1996(E) Provided by IHS under license with ISO Not for Resale ISO 1279:1996(E) FOREWORD Iso (the International Organization for Standardization) is a worldwide federation of national 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 inthe work.IsO collaborates closelywith the International Electrotechnical Commission (IEC) on all mattersofelectrotechnicalstandardization. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. International Standard ISO 1279 was prepared by Technical Committee ISO/TC 54, Essential oils. This third edition cancels and replaces the second edition (ISO 1279:1984), which has been technically revised. @ISO1996 All rights reserved.Unless otherwise specified,nopart of thispublication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, withoutpermission in writingfromthepublisher. International OrganizationforStandardization Casepostale56.CH-1211Geneve20.Switzerland Internet [email protected] X.400 C=ch; a=400net; p=iso; o=isocs; s=central Printed inSwitzerland ii INTERNATIONALSTANDARD ISO ISO 1279:1996(E) Essential oilsDeterminationof carbonvl valuesPotentiometric methods using hydroxylammonium chloride 1 SCOPE This International Standard specifies two methods for the potentiometric determination of the carbonyl valueof essential oilswhichcontaincarbonylcompounds,eitheraldehydesorketones. Method I (see clause 5), is based on a cold oximation reaction with hydroxylammonium chloride. It applies to essential oils whose main constituents are easily oximable aldehydes and ketones, with the exception of citronellal which needs a low temperature to avoid cyclization phenomena and acetalization. NOTE 1 In the case of citronellal the free hydroxylamine method described in ISO 1271 should be used. NOTE 2 Examples of essential oils concerned are lemongrass, hesperydus and rue. Method ll (see clause 6), is based on a hot oximation reaction with hydroxylammonium chioride. It applies to essential oils whose main constituents are ketones which are in general oximable only with difficulty. NOTE 3 Examples of essential oils concerned are vetiver, Dalmation sage and white artemisia which contain methylketones oximable only with difficulty. The International Standard for a specific essential oil will specify the method to be used, whether this is the free hydroxylamine method described in IsO 1271 or another method. 2 NORMATIVEREFERENCES The following standards contain provisions which, through reference in this text, constitute provisions of this International Standard. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this International Standard are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below. Members of IEC and isO maintain registers of currently valid International Standards. ISsO 212:1973, Essential oils - Sampling. No reproduction or networking pemitted without license from IHS