ISO INTERNATIONAL STANDARD 15517 First edition 2003-04-15 Tobacco Determination of nitrate content Continuous-flow analysis method Tabac Détermination de la teneur en nitrates -Méthode par analyse en flux continu Reference number ISO 15517:2003(E) @ ISO 2003 No reproduction or networking permitted without license from IHS Not for Resale ISO15517:2003(E) PDF disclaimer This PDF file may contain embedded typefaces. In accordance with Adobe's licensing policy, this file may be printed or viewed but shall not be edited unless the typefaces which are embedded are licensed to and installed on the computer performing the editing. In accepts no liability in this area. Adobe is a trademark of Adobe Systems Incorporated. parameters were optimized for printing. Every care has been taken to ensure that the file is suitable for use by ISO member bodies. In the @ISO2003 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 either Iso at the address below or Iso's member body in the country of the requester. ISO copyright office Case postale 56·CH-1211 Geneva 20 Tel. + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail [email protected] Web www.iso.org Published in Switzerland @ ISO 2003 - All rights reserved No reproduction or networking permited without license from IHS Not for Resale ISO 15517:2003(E) Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies technicalcommittees.Eachmemberbodyinterestedinasubjectforwhichatechnicalcommitteehasbeer non-governmental, in liaison with IsO, also take part in the work. ISO collaborates closely with the International International Standards are drafted in accordance with the rules given in the ISO/lEC Directives, Part 2. 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. 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. ISO 15517 was prepared by Technical Committee ISO/TC 126, Tobacco and tobacco products, Subcommittee SC 2, Leaf tobacco. CoyhtIemationalOganzatadardizatoghtrerved ili Not fr Resale Copyright intenatioal Organizatin for Standardization No reproduction or networking permitted without license from IHS Not for Resale INTERNATIONAL STANDARD ISO 15517:2003(E) Tobacco Determination of nitrate content Continuous-flow analysis method 1 Scope This International Standard specifies a method for the determination of the nitrate content in tobacco by continuous-flow analysis. This method is applicable to manufactured and unmanufactured tobacco. 2 Principle An aqueous extract (see below) of the tobacco is prepared and the nitrate content of the extract is determined ethylenediamine dihydrochloride to form a coloured complex, which is measured at 520 nm. If there is any nitrite content, it will be detected and included in the nitrate content result. extracts. It is recommended that 5 % acetic acid extracts should be used if nitrate and reducing substances (see IsO 15153) or reducing carbohydrate analyses (see ISO 15154) are to be carried out simultaneously. 3 Reagents All reagents shall be used according to good laboratory practice and existing national regulations. Use distilled water or water of at least equivalent purity. 3.1 Polyoxyethylene lauryl ether (Brij 35 solution) Add 1 litre of water to 250 g of Brij 35. Warm and stir until dissolved. 3.2 Sodium hydroxide solution (NaOH), p.a. Dissolve 8,0 g of sodium hydroxide in distilled water. Add 1 ml of Brij 35 solution (3.1) and dilute to 1 litre. 3.3 Copper sulfate stock solution (CuSO4), p.a. Dissolve 1,20 g of cop