ISO INTERNATIONAL STANDARD 9964-3 First edition 1993-05-01 Water quality Determination of sodium and potassium Part 3: Determination of sodium and potassium by flame emission spectrometry Qualité de I'eau - Dosage du sodium et du potassium Partie 3: Dosage par spectrometrie d'emission de flamme Reference number ISO9964-3:1993(E) ISO 9964-3:1993(E) Foreword IsO (the International Organization for Standardization) is a worldwide of preparing International Standards is normally carried out through IsO technicalcommittees.Each memberbodyinterestedin asubject for which a technical committee has been established has the right to be and non-governmental, in liaison with isO, also take part in the work. IsO collaborates closely with the International Electrotechnical Commission (lEC) 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 9964-3 was prepared by Technical Committee iSO/TC 147, Water quality, Sub-Committee SC 2, Physical, chemical, biochemicalmethods. IsO 9964 consists of the following parts, under the general title Water quality -- Determination of sodium andpotassium: -Part 1:Determination of sodium by atomic absorption spectrometry Part 2: Determination of potassium by atomic absorption spec- trometry Part 3: Determination of sodium and potassium by flame emission spectrometry Annex A of this part of ISO 9964 is for information only. ISO1993 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-1211Geneve 20·Switzerland Printed in Switzerland ii ISO 9964-3:1993(E) INTERNATIONAL STANDARD Water quality --- Determination of sodium and potassium Part 3: Determination of sodium and potassium by flame emission spectrometry Scope ISO 5667-1:1980, Water quality Sampling 1 Part 1: Guidance on the design of sampling pro- grammes. 1.1 Field of application ISO5667-2:1991,Water quality Sampling This International Standard specifies a method for the Part 2: Guidance on sampling techniques. determination of dissolved sodium and potassium by flame emission spectrometry (FES). It is intended for the analysis of raw and drinking waters. 3Principle The method is applicable to water samples with a Aspiration of the sample into a gas flame of sufficient mass concentration of sodium and potassium of up to 10 mg/l. For samples containing higher concen- present to emit its characteristic radiation. Measure trations of sodium and potassium, a smaller test por- ment of the intensity at a wavelength of 589,0 nm for tion is taken for analysis. The lower limits of sodiumand766,5nmforpotassium. determination are less than 0,1 mg/l for both sodium and potassium. When using the air/acetylene fiame, the addition of caesium chloride solution as an ionization buffer is necessary. 1.2 Interferences The ions normally present in raw and drinking waters 4 Reagents do not interfere with the flame emission spectro metric method for sodium and potassium if an During the analysis, use only reagents of recognized ionization suppressant is present. analytical grade and oniy deionized water or water of equivalent purity. 2 Normative references 4.1 Hydrochloric acid, c(HCl) 11 mol/l, p =1,18g/ml. The following standards contain provisions which, through reference in this text, constitute provisions of this part of ISO 9964. At the time of publication, the 4.2 Nitric acid, c(HNO3) ~ 16 mol/l, p = 1,41 g/ml. editions indicated were valid. All standards are subject to revision, and parties to agreements based on this 4.3 Caesium chloride, (CsCl), solution. part of IsO 9964 are encouraged to investigate the possibility of applying the most recent editions of