ISO INTERNATIONAL STANDARD 9698 Third edition 2019-05 Water quality - Tritium Test method using liquid scintillation counting Qualité de I'eau- Tritium - Méthode d'essai par comptage des scintillations en milieu liquide Reference number ISO 9698:2019(E) so @ IS0 2019 IS0 9698:2019(E) COPYRIGHTPROTECTEDDOCUMENT @ ISO 2019 All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior written permission. Permission can be requested from either IsO at the address below or Iso's member body in the country of the requester. ISO copyright office CP 401 : Ch. de Blandonnet 8 CH-1214 Vernier, Geneva Phone: +4122 749 0111 Fax: +41 22 749 09 47 Email: [email protected] Website: www.iso.org Published in Switzerland ii @ IS0 2019 - All rights reserved IS0 9698:2019(E) Contents Page Foreword ..iv Introduction. ..V 1 Scope. ..1 2 Normative references 3 Terms, definitions and symbols ..1 3.1 Terms and definitions 3.2 Symbols.... 4 Principle .2 5 Reagents and equipment. .3 5.1 Reagents. 3 5.1.1 Water for the blank. .3 5.1.2 Calibration source solution .4 5.1.3 Scintillation solution. 4 5.1.4 Quenching agent 4 5.2 Equipment. .4 5.2.1 General 4 5.2.2 Liquid scintillation counter ..5 5.2.3 Counting vials .5 6 Sampling and samples .5 6.1 Sampling and sample transportation. ..5 6.2 Sample storage .6 7 Procedure .6 7.1 Sample preparation .6 7.1.1 General. .6 7.1.2 Direct procedure ..6 7.1.3 Distillation 7.2 Preparation of the sources to be measured .6 7.3 Counting procedure .7 7.3.1 General 7 7.3.2 Control and calibration 7 7.3.3 Measurement conditions .8 7.3.4 Interference control. .8 8 Expression of results .9 8.1 General .9 8.2 Calculation of activity concentration .9 8.3 Decision threshold 10 8.4 Detection limit .10 8.5 Confidence interval limits ..11 8.6 Calculations using the activity per unit of mass ..11 6 Test report ..11 Annex A (informative) Numerical applications .13 Annex B (informative) Distillation of large volume sample .14 Annex C (informative) Internal standard methods ..17 Annex D (informative) Distillation of small volume sample ..19 Annex E (informative) Simplified distillation ..22 Bibliography .24 @ IS0 2019 - All rights reserved iii