ISO INTERNATIONAL STANDARD 15604 Firstedition 2016-05-01 FertilizersDeterminationof different forms of nitrogen in the same sample, containing nitrogen as nitric, ammoniacal, urea and cyanamide nitrogen Engrais-Determination des differentesformesd'azote dans un meme échantillon contenant I'azote sous forme nitrique, ammoniacale,ureiqueetcyanamidique Reference number IS015604:2016(E) ISO Intemational Organization for Standardization @IS02016 HEJIANG INST OF STANDARDIZATION C1 5956617 ed without license from IHS IS015604:2016(E) COPYRIGHTPROTECTEDDOCUMENT IS02016,Published inSwitzerland All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below or ISO's member body in the country of the requester. ISo copyright office Ch. de Blandonnet 8. CP 401 CH-1214 Vernier, Geneva, Switzerland Tel. +41 22 749 01 11 Fax +4122 749 09 47 copyright@iso.org www.iso.org Uicensee-ZHEJIANG INSTOF STANDARDIZRoISQ,6-All rights reserved etworking permitted without license from IHS Not for Resale, 2016/7/20 03:23:2 Noreproduction IS0 15604:2016(E) Contents Page Foreword ..iv 1 Scope. 2 Normative references 3 Terms and definitions 4 Principle 4.1 Total soluble and insoluble nitrogen .1 4.2 Forms of soluble nitrogen .2 4.2.1 General 2 4.2.2 Total soluble nitrogen .2 4.2.3 Total soluble nitrogen with the exception of nitrate nitrogen 2 4.2.4 Nitrate nitrogen by difference. .2 4.2.5 Ammoniacal nitrogen 2 4.2.6 Ureanitrogen .2 4.2.7 Cyanamide nitrogen. .3 5 Reagents .3 6 Apparatus. 7 Samplingand samplepreparation ..10 8 Procedure .10 8.1 Total solubleand insolublenitrogen .10 8.1.1 In the absence of nitrates ..10 8.1.2 Inthepresence ofnitrate .11 8.2 Forms ofsolublenitrogen. .12 8.2.1 Preparation ofthe solution to be analysed .12 8.2.2 Total soluble nitrogen .13 8.2.3 Total soluble nitrogen with the exception of nitrate nitrogen. .14 8.2.4 Nitrate nitrogen. ..14 8.2.5 Ammoniacal nitrogen ..15 8.2.6 Urea nitrogen ..16 8.2.7 Cyanamide nitrogen ..18 9 Verification oftheresult. .18 10 Test report .18 Bibliography .19 iii See=ZHEJIANG INSTOFSTANDARDIZATIONC15956617 ithout license from IHS