150 10084 92 4851903 0522448 070 ISO INTERNATIONAL STANDARD 10084 First edition 1992-12-01 Solid fertilizers Determination of mineral-acid-soluble sulfate content Gravimetric method Matieres fertilisantes solides - Détermination de la teneur en sulfates solubles dans les acides minéraux - Méthode gravimétrique Reference number ISO 10084:1992(E) Copyright International OrganizationforStandardization JotforResa 201 6th2250 E06T5h 26 h900 051 ISO 10084:1992(E) Foreword IsO (the International Organization for Standardization) is a worldwide federation of national standards bodies (IsO member bodies). The work of preparing International Standards is normally carried out through iso which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. iso/Tc 134, Fertilizers and soil conditioners, Sub-Committee SC 4, Chemicalanalysis. @SO1992 All rights reserved. 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 per- mission in writing from the publisher. International Organization for Standardization Case Postale 56· CH-1211 Geneve 20· Switzerland Printed in Switzerland Copyright International Organization for Standardization Not for Resale 622 05h2250 150 10084 92 E06TS ISO 10084:1992(E) INTERNATIONAL STANDARD Solid fertilizers Determination of mineral-acid-soluble sulfate content - Gravimetric method dihydrate solution, Scope 4.2 Barium chloride 1 c(BaCl2:2H20) = 122 g/l. This International Standard specifies a method for the 4.3 Silver nitrate solution, c(AgNO3) = 5 g/l. gravimetric determination of the mineral-acid-soluble sulfate content of solid fertilizers. The method is ap plicable to fertilizers with sulfate contents, expressed Apparatus 5 as SO3. from 3 % (m/m) to 50 % (m/m). Ordinary laboratory apparatus and the following. 2 Normative reference 5.1 Electric hot-plate The following standard contains provisions which, through reference in this text, constitute provisions 5.2 Filter crucibles with porcelain disc, porosity of this International Standard. At the time of publica- grade P10, pore size index 4 μm to 10 μm. tion, the edition indicated was valid. All standards are subject to revision, and parties to agreements based 5.3 Oven, capable of being maintained at a tem- on this International Standard are encouraged to in- perature of 120 °C ± 5 °C. vestigate the possibility of applying the most recent edition of the standard indicated below. Members of 5.4 Oven, capable of being maintained at a tem- IEC and ISO maintain registers of currently valid perature of 800 °C ± 50 °C. International Standards. ISO 8358:1991, Solid fertilizers Preparation of 5.5 Desiccator, filled with a suitable desiccant. samples for chemical and physical analysis. 61 Preparation of the test sample 3Principles Prepare the laboratory sample according to IsO 8358 and transfer at least 50 g to the laboratory for analy- Dissolution of soluble sulfates in hydrochloric acid sis. solution. Precipitation of sulfate ions in a hydrochloric acid medium with barium chloride. Filtration, washing. drying, ignition and weighing of the precipitate. 7 Procedure 7.1 Test portion Reagents 4. Weigh, to the nearest 0,1 mg, the mass of the test All -reagents shall be of recognized analytical grade sample (clause 6) which, according to table 1, corre- The water used shall be distilled water or water of sponds with the expected acid-soluble sulfate con- equivalent purity. tent. The amount of sOs present in the test portion NOTE 1