ISO INTERNATIONAL 54321 STANDARD First edition 2020-08 Soil, treated biowaste, sludge and waste Digestion of aqua regia soluble fractions of elements Sols, biodéchets traites, boues et déchets -Digestion des éléments solubles dans I'eau regale Reference number IS054321:2020(E) ISO @IS02020 IS054321:2020(E) COPYRIGHTPROTECTEDDOCUMENT ISO2020 All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may below or ISo's member body in the country of the requester. ISO copyright office CP 40i : Ch. de Blandonnet 8 CH-1214 Vernier, Geneva Phone: +41 22 749 01 11 Email: [email protected] Website: www.iso.org Published in Switzerland ii IS02020-Allrights reserved IS0 54321:2020(E) Contents Page Foreword iv Introduction A 1 Scope 2 Normativereferences .1 3 Terms anddefinitions .1 4 Principle .2 5 Interferencesandsourcesoferrors .2 6 Reagents .3 3 7 Apparatus. General 3 7.1 7.2 MethodAApparatusforthermal heatingunderatmospheric conditions 3 7.2.1 Method A1-Thermal heating under reflux conditions. 3 7.2.2 MethodA2-Thermal heatingwithaheatingblockwith containers 4 7.3 Method B-Microwavedigestion with temperature control, closed vessels 4 8 Procedure. 8.1 General. 8.2 Blanktest 5 8.3 MethodAthermal heatingunderatmosphericconditions 5 8.3.1 Method A1Thermal heating under reflux conditions 5 8.3.2 MethodA2-Thermal heatingwithaheatingblockwithcontainers 6 8.4 Method BMicrowave digestion withtemperature control, closed vessels 7 9 Testreport 7 Annex A (informative) Repeatability and reproducibility data for soil, biowaste and sludge samples 9 AnnexB (informative)Repeatabilityandreproducibilitydataforwastesamples .10 Bibliography .37 @ IS0 2020 - All rights reserved iii