ISO INTERNATIONAL STANDARD 23157 First edition 2021-07 Determination of the silanol group content on the surface of fumed silica Reaction gas chromatographic method Referencenumber IS0 23157:2021(E) ISO IS02021 IS0 23157:2021(E) COPYRIGHT PROTECTED DOCUMENT @ iS0 2021 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: +41 22 749 0111 Email: [email protected] Website: www.iso.org Published in Switzerland i @ IS0 2021 - All rights reserved