ISO INTERNATIONAL STANDARD 11216 First edition 1998-05-15 Modified starch Determination of content of carboxymethyl groups in carboxymethyl starch Amidons et fecules modifieés - Détermination des groupes carboxymethyles dans I'amidon carboxyméthylé ISO Referencenumber ISO11216:1998(E) py IHS under lic Not for Resale ISO 11216:1998(E) Foreword IsO (the International Organization for Standardization) is a worldwide federationofnationalstandardsbodies(lsOmemberbodies).Theworkof 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 sO, also take part in the work. isO collaborates closely with the International Electrotechnical Commission (lEC)onallmattersofelectrotechnicalstandardization. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. International Standard ISO 11216 was prepared by Technical Committee ISO/TC 93, Starch (including derivatives and by-products) @ISO1998 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced microfilm, without permission in writing from the publisher. International OrganizationforStandardization Case postale 56 · CH-1211 Geneve 20 · Switzerland Internet [email protected] X.400 C=ch; a=400net; p=iso; 0=isocs; S=central Printed in Switzerland Not for Resale INTERNATIONAL STANDARD @ ISO ISO 11216:1998(E) Modified starch Determination of content of carboxymethy groups in carboxymethyl starch 1 Scope This International Standard specifies a method for the determination of the content of carboxymethyl groups in carboxymethyl starch. The method is suitable for determining carboxymethyl group contents between 1,6 % (m/m) and 10,0 % (m/m). 2 Normative references The following standards contain provisions which, through reference in this text, constitute provisions of this InternationalStandard.Atthetime of thepublication,the editions indicated werevalid.All standardsare subjectto revision, and parties to agreements based on the International Standard are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below. Members of IEC and ISO maintain registers of currently valid International Standards. IsO 1666:1996, Starch Determination of moisture content - Oven-drying method. IsO 3696:1987, Water for analytical laboratory use Specification and test methods. 3 Definition For the purposes of this International Standard, the following definition applies. 3.1 carboxymethyl group content the acid form NOTE The carboxymethyl group content is expressed as a percentage by mass. 4 Principle The carboxymethyl groups are converted into the acid form by acidifying a solution or a suspension of the starch a sintered glass crucible. The excess acid is completely removed by washing with methanol. The starch is dried and aweighedportionistreatedwithameasuredexcessof sodiumhydroxidesolution.Thesodiumhydroxidenot used by the sample is back-titrated with hydrochloric acid. ional Organization for Standardizatior