ISO INTERNATIONAL STANDARD 11905-1 First edition 1997-05-01 Water quality --- Determination of nitrogen - Part 1: Method using oxidative digestion with peroxodisulfate Qualitede I'eau-Dosage de I'azote- Partie 1: Methode par mineralisation oxydante au peroxodisulfate This material is reproduced from 1so documents under International Organization for Standardization (IsO) Copyright License number IHS/ICC/1996. Not for resale. No part of these ISO documents may be reproduced in any form, electronic retrieval system or otherwise, except as allowed in the copyright law of the country of use, or with the prior writen consent of iso (Case postale 56, 1211 Geneva 20, Switzerland, Fax +41 22 734 10 79), IHs or the isO Licensor's members. (so Reference number ISO 11905-1:1997(E) Copyright International Organization for Standardization No reproduction or networking permitted without license from IHS Not for Resale ISO 11905-1:1997(E) Contents Page 1 Scope 1 2 Normative references 3 Range of detection.. 4 Sensitivity.... 5 Principle. 2 6 Reagents. 2 7 Apparatus... 5 8 Sampling and samples. 5 9 Procedure 5 9.1 Test portion. 5 9.2 Blanktest 6 9.3 Cleaning digestion vessels .. 6 9.4 Digestion.... 6 9.5 Verification of recovery of organic nitrogen.... 6 9.6 Starting operation. 6 9.7 Initial sensitivity setting .... 8 9.8 Calibration.. 8 9.9 Determination. 8 10 Expression of results. 9 10.1 Method of calculation .. 6 10.2 Precision data 9 11 Testreport 9 @ISO1997 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 [email protected] X.400 C=ch;a=400net: p=iso; 0=isocs; s=central Printed in Switzerland ii Copyright International Organization for Standardizatior No reproduction or networking permitted without license from IHS Not for Resale ISO 11905-1:1997(E) @ ISO Annexes A 10 B Recovery data for some nitrogen-containing compounds .. 11 Determination of nitrate. 12 D 13 ili No reproduction or networking permitted without license from IHS Not for Resale