ISO INTERNATIONAL STANDARD 11262 Second edition 2011-11-15 Soil quality Determination of total cyanide Qualité du sol- Dosage des cyanures totaux Reference number ISO 11262:2011(E) LSO @ISO2011 IHS under lic n or networking permitted without license from IHS Not for Resale ISO 11262:2011(E) COPYRIGHTPROTECTEDDOCUMENT ISO2011 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 Casepostale56·CH-1211Geneva 20 Tel. + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail copyright@iso.org Web www.iso.org Published in Switzerland @ ISO 2011 -All rights reserved No reproductic etworking permitted without license from IHS Not for Resale ISO11262:2011(E) Contents Page Foreword .iy Introduction 1 Scope 2 Normative references 3 Terms and definitions. 4 Principle... 4.1 Direct liberation of hydrogen cyanide using orthophosphoric acid 2 4.2 Determination of total cyanide content. 2 5 Reagents... 2 5.1 Reagents for liberation and absorption of cyanide .. 2 5.2 Reagents for the photometric determination of cyanide. 5.3 Reagents for the titrimetric determination of cyanide ... 6 Apparatus 7 Sample preservation and preparation. 7.1 Sample preservation.. 5 7.2 Sample preparation.. 8 Direct liberation using orthophosphoric acid. 6 8.1 Procedure. 6 8.2 Blank test.. 6 9 Determination of cyanide Photometric method. 9.1 Applicability .. 9.2 Procedure.. 9.3 Preparation of the calibration graph. 9.4 Calculation 10 Determination of cyanide - Titrimetric method using an indicato 8 10.1 Applicability 8 10.2 Procedure 8 10.3 Calculation .9 11 Expression of results . 9 12 Precision. 10 13 Test report 10 Annex A (informative) Precision data. 11 Annex B (informative) Extraction with sodium hydroxide solution and subsequent liberation using orthophosphoricacid. 12 Annex C (informative) Comparison of the direct liberation of total cyanide and sodium hydroxide extraction with subsequent liberation. 15 Bibliography 16 ili license from IHS Not for Resale