ISO INTERNATIONAL STANDARD 23305 First edition 2020-04 Fortified milk powders, infant formula and adult nutritionals - Determination of total biotin by liquid chromatography coupled with immunoaffinity column clean-up extraction Poudres de lait fortifie, formules infantiles et produits nutritionnels pouradultesDeterminationdelateneurenbiotinetotale par chromatographie liquideapres unepurification sur colonne d'immunoaffinite Reference number IS0 23305:2020(E) ISO @IS02020 IS023305:2020(E) COPYRIGHTPROTECTEDDOCUMENT ISO2020 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 40i : 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 IS02020-Allrights reserved IS023305:2020(E) Contents Page Foreword iv 1 Scope .1 2 Normative references .1 3 Terms and definitions .1 4 Principle .1 5 Reagents and materials .2 5.1 2 General. 5.2 Reagent preparation 2 5.3 Standard preparation. 3 5.4 Calculationofconcentration 4 6 .4 Apparatus 7 Procedure. 5 7.1 Samplepreparation 5 7.2 Chromatography 6 7.3 Quality control. 7 8 Calculations. 7 9 Precision .8 9.1 General. 8 9.2 Repeatability 8 9.3 Reproducibility 8 10 Uncertaintyofmeasurement .8 11 Limit of quantitation 9 AnnexA(informative)Examplechromatograms .10 AnnexB (informative)Precisiondata .12 AnnexC (informative)ComparisonbetweenthisdocumentandEN15607 .14 Bibliography .16 @IS0 2020 - All rights reserved iii