6636/2 International Standard (ISO INTERNATIONAL ORGANIZATION FOR STANDARDIZATIONMEXAYHAPOAHAR OPTAHW3AWR IO CTAHAAPTW3AUMWORGANISATION INTE RNATIONALE DE NORMALISATION Fruits, vegetables and derived products -- Determination of zinc content Part 2 : Atomic absorption spectrometric method Fruits, legumes et produits dériveés -- Détermination de la teneur en zinc -- Partie 2 : Methode par spectrometrie d'absorption atomique First edition - 1981-10-15 U D C 634/635 : 543.42 : 546.47 Ref. No. ISO 6636/2-1981 (E) :0 6636/2-1981 ( Descriptors : agricultural products, food products, fruits, vegetables, tests, determination of content, zinc, atomic absorption spectroscopic analysis. Price based on 4 pages Not forResale 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 Internationat Standards by the ISo Council. Standard Iso 6636/2 was developed by Technical Committee International ISO/TC 34, Agricultural food products, and was circulated to the member bodies in December 1979. It has been approved by the member bodies of the following countries : Hungary Portugal Australia Austria India Romania Ireland South Africa, Rep. of Brazil Spain Bulgaria Israel Canada Italy Thailand Czechoslovakia Korea, Rep. of Turkey Ethiopia Netherilands USSR France New Zealand Yugoslavia Germany, F. R. Poland No member body expressed disapproval of the document. International Organization for Standardization, 1981 Printed in Switzerland Copyright International Organization for Standardization Not for Resal INTERNATIONAL STANDARD ISO 6636/2-1981 (E) Fruits, vegetables and derived products Determination of zinc content : Part 2 : Atomic absorption spectrometric method 1 Scope and field of application 4.4 Hydrochloric acid, approximately 3,7 g/l solution. This part of Iso 6636 specifies an atomic absorption spec- In a 1 000 ml one-mark volumetric flask, djlute 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 2 References litre. In a conical flask, dissolve 1 g of pure zinc in 10 ml of the ISo 5515, Fruits, vegetables and derived products - Decom- hydrochloric acid solution (4.3). Transfer quantitatively to a position of organic matter prior to analysis -- Wet method. 1 000 ml one-mark volumetric flask, dilute to the mark with ISo 5516, Fruits, vegetables and derived products - Decom- water, and mix. position of organic matter prior to analysis - Ashing method. 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 trometry. following : 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 with polyethylene. into easily dissociable chlorides. 5.2 Platinum or quartz dishes, of diameter 70 mm, or For some liquid samples (such as wines, clear fruit juices free Kjeldahl flasks, of capacity 250 ml. from pulp), the determination may be carried out directly, without previous decomposition. 5