BS IS0 20702:2017 INTERNATIONAL ISO STANDARD 20702 First edition 2017-12-10 Fertilizers and soil conditioners Determination of microamounts of inorganic anions in fertilizers by ion chromatography EngraisetamendementsDéterminationdesmicroquantités d'anions inorganiques dans les fertilisants par chromatographie d'échange d'ions Reference number A IS0 20702:2017(E) ISO @ IS0 2017 BSIS0 20702:2017 IS0 20702:2017(E) COPYRIGHTPROTECTEDDOCUMENT IS0 2017, Published in Switzerland All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form 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 copyrightoffice Ch. de Blandonnet 8 . CP 401 CH-1214 Vernier, Geneva, Switzerland Tel. +41 22 749 01 11 Fax +41 22 749 09 47 copyright@iso.org www.iso.org ii @ IS0 2017 - All rights reserved BS IS0 20702:2017 IS0 20702:2017(E) Contents Page Foreword ..iv Introduction. ..V 1 Scope. ..1 2 Normative references ..1 3 Terms and definitions 4 Principle .1 5 Reagents. ..1 6 ..3 Apparatus and materials. 7 Test procedure .4 7.1 General. .4 7.2 Preparation of test sample 7.3 Activation of the filter columns .4 7.4 Preparation of the test solution 4 7.5 Ion chromatography condition A (Gradient chromatography condition) 7.6 Ion chromatography condition B (Isocratic chromatography condition) ..6 7.7 Determination of standard working solutions and sample test solutions .6 8 Calculation and expression of results .7 8.1 General. 7 8.2 Precision 7 8.2.1 Ring test .7 8.2.2 Repeatability, I 7 8.2.3 Reproducibility, R .7 9 Test report .7 Annex A (informative) Ring test report - Report of international laboratories ring test ..9 Annex B (informative) Typical ion chromatogram for gradient chromatography conditions. ..46 Annex C (informative) Typical ion chromatogram for isocratic chromatography conditions. ...47 Annex D (informative) Additional statistical index of the test results .48 Bibliography .50 @ IS0 2017 - All rights reserved iii