BS ISO BRITISH STANDARD 20481:2008 Coffee and coffee products - Determination of the caffeine content using high performance liquid chromatography (HPLC) Reference method ICS 67.140.20 BSi NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW British Standards BSISO20481:2008 National foreword This British Standard is the UK implementation of IS0 20481:2008 The UK participation in its preparation was entrusted to Technical Committee Aw/15,Coffee. A list of organizations represented on this committee can be obtained on request to its secretary. 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 cannot confer immunity from legal obligations. This British Standard was Amendments/corrigenda issued sincepublication published under the authority of the Standards Policy and Date Comments Strategy Committee on30June2008 BSI 2008 ISBN9780580575532 BSIS0 20481:2008 ISO INTERNATIONAL STANDARD 20481 First edition 2008-05-01 Coffee and coffee products Determinationof the caffeine content using high performance liquid chromatography (HPLC) Reference method Cafe etderivesdu cafe-Determinationdela teneuren cafeinepar chromatographie liquidea hauteperformance(CLHP)-Methode de reference Reference number ISO 20481:2008(E) O ii BSIS0 20481:2008 Foreword IsO (the International Organization for Standardization) is a worldwide federation of national standards bodies International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. 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. rights. IsO shall not be held responsible for identifying any or all such patent rights. ISO20481waspreparedbyTechnical CommitteeISO/TC34,Foodproducts,SubcommitteeSC15,Coffee i blank BSIS0 20481:2008 Coffee and coffee products Determination of the caffeine content using high performance liquid chromatography (HPLC) Reference method 1 $ Scope This International Standard specifies a high performance liquid chromatography (HPLC) method for the determination of the caffeine content of: green coffee; roasted coffee; soluble coffee, regular and decaffeinated; and mixed instant coffee products (e.g.coffee/chicory mix or cappuccino-type coffee drink) 2Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced Iso 565,Test sieves-Metal wire cloth, perforated metal plate and electroformed sheet-Nominal sizes of openings Iso648,Laboratoryglassware-Singlevolumepipettes ISO1042,Laboratoryglassware-One-markvolumetricflasks IsO3696,Waterforanalyticallaboratoryuse-Specificationandtestmethods IsO3726,Instantcoffee-Determinationoflossinmassat7oCunderreducedpressure ISO6673,Greencoffee-Determinationoflossinmassat105C ISO11817,Roastedground coffee-Determinationofmoisturecontent-KarlFischermethod(Reference method) Principle Caffeine is extracted from samples with water at 9o °C in the presence of magnesium oxide. After filtration the caffeine content of the extract is determined by HPLC on a RP-18 column using isocratic elution with UV detection at approximately 272 nm. Wherever appropriate, the caffeine content may be given on dry basis which requires a moisture determinationbyasuitablestandardmethod 4 Reagents Unless otherwise specified, use only reagents of recognized analytical grade, and only water conforming to the requirements of isO 3696, grade 1. 4.1 Methanol, HPLC grade 1