6636/2 International Standard OSI) INTERNATIONAL ORGANIZATION FOR STANDARDIZATIONMEKAYHAPOAHAR OPTAHM3AUMA NO CTAHAAPTM3AUWM+ORGANISATION INTERNATIONALE DE NORMALISATION Fruits, vegetables and derived products - Determination of zinc content Part 2 : Atomic absorption spectrometric method Fruits, legumes et produits derives --Determination de la teneur en zinc -Partie 2: Methode par spectrometrie d'absorption atomique First edition -1981-10-15 ISO 6636/2-1981 (E) UDC634/635:543.42:546.47 Ref.No.1SO6636/2-1981 (E) Descriptors :agricultural products, food products, fruits, vegetables, tests, determination of content, zinc, atomic absorption spectroscopic analysis. Price based on 4 pages Foreword iso (the International Organization for Standardization)is a worldwide federation of national standards institutes (iso member bodies). The work of developing Inter- national Standards is carried out through ISo technical committees. Every member body interested in a subject for which a technical committee has been set up has the right to be represented on that committee. International organizations,governmental and non-governmental, in liaison with Iso, also take part in the work. Draft International Standards adopted by the technical committees are circulated to the member bodies for approval before their acceptance as International Standards by the ISo Council. International Standard ISo6636/2 wasdeveloped byTechnicalCommittee ISO/TC 34, Agricultural food products, and was circulated to the memberbodies in December1979. It has been approved by the member bodies of the following countries : Hungary Portugal Australia Austria India Romania Ireland South Africa, Rep. of Bulgaria Israel Spain Canada Italy Thailand Korea, Rep. of Turkey Czechoslovakia Ethiopia Netherlands USSR France New Zealand Yugoslavia Germany, F. R. Poland No member body expressed disapproval of the document. InternationalOrganizationforStandardization,1981 Printed in Switzerland INTERNATIONALSTANDARD ISO6636/2-1981 (E) Fruits, vegetables and derived products - Determination of zinc content - Part 2 : Atomic absorption spectrometric method 1 Scopeandfieldofapplication 4.4Hydrochloric acid,approximately3,7g/l solution. This part of ISo 6636 specifies an atomic absorption spec- In a 1 000 ml one-mark volumetric flask, dilute 8,3 ml of con- trometric method for the determination of the zinc content of centrated hydrochloric acid (020 = 1,19 g/ml) to the mark with fruits, vegetables and derived products. water and mix. 4.5 Zinc,standard solution corresponding to 1 g of zinc per 2References litre. Inaconical flask,dissolve1gofpurezinc in10ml of the ISo5515,Fruits,vegetablesandderivedproducts-Decom- hydrochloric acid solution (4.3). Transfer quantitatively to a positionoforganicmatterpriortoanalysis-Wetmethod. 1 000 ml one-mark volumetric flask, dilute to the mark with Iso5516,Fruits,vegetablesandderivedproducts-Decom- water, and mix. positionoforganicmatterpriortoanalysisAshingmethod. Store the solution in a bottle of borosilicate glass fitted with a ground glass stopper. 3Principle 5 Apparatus Decomposition of organic matter by the dry or wet method and determination of the Zn2+ cation by atomic absorption spec- Usual laboratory equipment not otherwise specified, and the following : trometry. NOTE - In the case of decomposition by the dry method, dissolution 5.1 Mechanical grinder, the inside and blades of which are of the ash in hydrochloric acid allows transformation of all mineral salts coated withpolyethylene. into easily dissociable chlorides. 5.2. Platinum orquartzdishes,of diameter70mm,or Forsomeliquid samples (suchaswines,clearfruit juicesfree Kjeldahl flasks, of capacity 250 ml. from pulp), the determination may be carried out directly, withoutpreviousdecomposition. 5.3One-markvolumetric flasks,of capacity50ml. 5.4 Volumetric pipettes,of appropriate capacities. 4Reagents All reagents shall be of recognized analytical purity, and shall 5.5 Centrifuge. be especiall