ISO INTERNATIONAL STANDARD 10693 First edition 1995-03-15 Soil quality --- Determination of carbonate content Volumetric method Qualite du sol --- Determination de la teneur en carbonate - Methode volumetrique ISO Reference number ISO 10693:1995(E) No reproduction or networking permited without license from IHS Not for Resale ISO10693:1995(E) Foreword ISO (the International Organization for Standardization) is a woridwide 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. Draft International Standards adopted by the technical committees are 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 190, Soil quality, Subcommittee SC 3, Chemical methods and soil characteristics ISO1995 Allrights 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 the publisher International Organization for Standardization Case Postale 56· CH-1211 Geneve 20· Switzerland Printed in Switzerland ii Copyright International Organization for Standadization ed without license from IHS Not for Resale IS0 10693:1995(E) INTERNATIONAL STANDARD ISO Soil quality Determination of carbonate content - Volumetric method 1 Scope 3Principle This International Standard specifies a method for the Hydrochloric acid is added to a soil sample to de- determination of carbonate content in soil samples. compose any carbonates present. The reaction in simplified form reads as follows (Me means metal): It is applicable to all types of air-dried soil samples. MeCO3 + 2H+ → Me2+ + H2CO3 2 Normative references H,CO3 → H2O + CO2 (gaseous state) The following standards contain provisions which, The volume of the carbon dioxide produced is meas- through reference in this text, constitute provisions uredbyusingaScheibler apparatus(5.1),andis of this International Standard. At the time of publica- compared with the volume of carbon dioxide pro- tion, the editions indicated were valid. All standards duced by pure calcium carbonate. To avoid making are subject to revision, and parties to agreements corrections for differences in temperature and press- based on this International Standard are encouraged ure,all determinations are carriedout underthe same to investigate the possibility of applying the most re- conditions. The determination should be carried out in cent editions of the standards indicated below. a temperature-controlled room. Members of IEC and iSO maintain registers of cur- rently valid Internationai Standards. NOTES Iso 3696:1987,Water for analytical laboratoryuse- 1The carbonatecontent isexpressed as an equivalent concentration of calcium carbonate (CaCOg). in fact all car- Specification and test methods. bonates andbicarbonatespresent inthe sample aremeas ured. Many carbonates appear in the form of calcite and Is0 11464:1994, Soil quality - Pretreatment of sam- aragonite (CaCO3), dolomite [CaMg(CO3)2], siderite (FeCO3) ples for physico-chemical analyses. and rhodochrosite(MncO,).Insoils in dry(arid)regions soda (Na,CO3:10H2O) may be present. When it is known 1sO 11465:1993, Soil quality - Determination of dry that a certain form of carbonate, other than calcium matter and water content on a mass basis carbonate, is mainly present in the soil under study, the final Gravimetric method. concentrationof thisformcanbeused. 1 Copyright International Organization for Standardizatior Not for Resale