BS ISO BRITISH STANDARD 18252:2006 Anhydrous milk fat Determination of sterol composition by gas liquid chromatography (Routine method) ICS 67.100.01 BSi NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW British Standards BSISO18252:2006 National foreword ThisBritish Standard reproduces verbatimISO18252:2006 andimplements it as theUK national standard. The UK participation in its preparation was entrusted to Technical Committee AW/5, Chemical analysis of milk and milk products, which has the responsibility to: aid enquirers to understand the text; present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep UK interests informed; monitor related international and European developments and promulgate them in the UK. A list of organizations represented on this committee can be obtained on request to its secretary. Cross-references The British Standards which implement international publications referred to in this document may be found in the BSI Catalogue under the section entitled "International Standards Correspondence Index", or by using the“Search" facility of the BSI Electronic Catalogue or of British Standards Online. This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. Compliance with a British Standard does not ofitself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, the IsO title page, pages ii to v, a blank page, pages 1 to 13 and a back cover. The BSI copyright notice displayed in this document indicates when the document was last issued. Amendments issued sincepublication This British Standard was Amd. No. Date Comments published under the authority of the Standards Policy and Strategy Committee on 15February 2006 @ BSI 15 February 2006 ISBN058047836X BSIS018252:2006 ISO INTERNATIONAL 18252 STANDARD IDF 200 First edition 2006-02-01 Anhydrous milk fat Determination of sterol composition by gas liquid chromatography (Routine method) Matieregrasseanhydredu lait-Determinationdela composition steroliquepar chromatographie liquide en phase gazeuse(Methode de routine) Reference numbers ISO 18252:2006(E) IDF 200:2006(E) ISO ii BS ISO 18252:2006 Contents Page Foreword. iv 1 Scope 2 Normative references 3 Terms and definitions. Principle.. 5 Reagents.. 6 Apparatus 7 Sampling. .5 8 Preparationoftestsample.. 5 9 Procedure.. 9.1 Sterol standard solutions. 9.2 Testportion... 9.3 Saponification... 9.4 Extractionoftheunsaponifiablematter.. 9.5 Qualitativeanalysis. 9.6 Quantitativeanalysis... 10 Precision. 10.1 Interlaboratorytest 10.2 Repeatability... 10.3 Reproducibility... 11 Test report .9 Annex A(informative) Example of the gas-liquid chromatographic analysis.. 10 Annex B (informative)Results of an interlaboratory trial. Bibliography. 13 ii BSIS018252:2006 Foreword Iso (the International Organization for Standardization) is a worldwide federation of national standards InternationalElectrotechnicalCommission(lEC)onallmattersofelectrotechnicalstandardization. International Standards are drafted in accordance with the rules given in the ISO/lEC Directives, Part 2 The main task of technical committees is to prepare International Standards. 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 avote rights. IsO shall not be held responsible for identifying any or all such patent rights. ISO18252|iDF200waspreparedbyTechnicalCommitteeISO/TC34,Foodproducts,SubcommitteeSC5 Milk and milk products, and the International Dairy Federation (IDF). It is being published jointly by ISO and IDF. iv BSISO18252:2006 Foreword Committee in every member country. Every National Committee has the right to be represented on the IDF Standing Committ