ISO INTERNATIONAL STANDARD 10566 First edition 1994-12-15 Water quality -- Determination of aluminium Spectrometric method using pyrocatechol violet Qualite de I'eau - Dosage de I'aluminium - Methode par spectrométrie a I'aide du violet de pyrocatéchol [So Reference number ISO 10566:1994(E) Copyright Intermational Organization for Standardization Not for Resale ISO10566:1994(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 technical committees. Each member body interested in a subject for 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 a vote. International Standard isO 10566 was prepared by Technical Committee ISO/TC147, Water quality. Subcommittee SC 2. Physical. chemical, biochemicalmethods @ISO 1994 All rights 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 International Organization for Standardization Case Postale 56. CH-1211 Geneve 20 · Switzerland Printed in Switzerland i No reproduction or networking permitted without license from IHS Not for Resale @ISO IS010566:1994(E) Introduction Aluminium occurs in a variety of types of compounds in nature, and can be found in acid, neutral and alkaline solutions. It can also form colloidat polymeric solutions and gels, as well as flocculant precipitates, all based on aquated positive ions or hydroxylated aluminates. In addition, it can form complexes with organic acids and with ions such as fluoride, chloride and suifate, most but not all of which are soluble. Aluminium can also form lattice compounds with oxygen (and hydroxyl species), silicon, and some metals. Although insoluble, some of these compounds, notably the clays, micas and zeolites, can be found as fine soluble lattice compounds are not usually considered as aluminium com- pounds in the context of the water cycle. The method described in this International Standard is restricted to the converted to that cationic form by acidification. The pretreatment with using spectrometric methods with an electrothermal atomization or in- ii Not for Resale