(ISO International Standard 6634 INTERNATIONAL ORGANIZATION FOR STANDARDIZATION MEXAYHAPOAHAA OPTAHW3AUWA HO CTAHAAPTM3ALWWORGANISATION INTERNATIONALE DE NORMALISATION Fruits, vegetables and derived products -- Determination of arsenic content - Silver diethyldithiocarbamate spectrophotometric method Fruits, légumes et produits derives -- Deétermination de la teneur en arsenic -- Methode spectrophotometrique au diethyldithiocarbamate d'argent First edition - 1982-12-01 UDC 634.1/635.6 : 543.42 : 546.19 Ref. No. ISO 6634-1982 (E) ISO 6634-1982 (E) Descriptors : agricultural products, fruits, vegetables, chemical analysis, determination of content, arsenic. Price based on 5 pages Copyright International Organization for Standardization Not for Resa Foreword iSo (the international Organization for Standardization) is a worldwide federation of national standards institutes (iso member bodies). The work of developing Inter- 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 cormmittees are circulated to the member bodies for approval before their acceptance as International Standards by the ISO Council. International Standard ISO 6634 was developed by Technical Committee ISO/TC 34, Agricuitural food products, and was circulated to the member bodies in June 1981. It has been approved by the member bodies of the following countries : Austria Iran Portugal Brazil Israel Romania Canada Kenya South Africa, Rep. of Czechoslovakia Korea, Dem. P. Rep. of Spain Egypt, Arab Rep. of Korea, Rep. of Sri Lanka Ethiopia Malaysia Tanzania France Netherlands Thailand Germany, F.R. Turkey New Zealand Hungary Philippines Yugoslavia India Poland The member body of the following country expressed disapproval of the document on technical grounds : Australia ? International Organization for Standardization, 1982 Printed in Switzerland Copyright International Organization for Standardization Not for Resale ISO 6634-1982 (E) INTERNATIONAL STANDARD Fruits, vegetables and derived products - Determination of arsenic content - Silver diethyldithiocarbamate spectrophotometric method Scope and field of application of blotting-paper folded into several layers, and allow to dry. Store in a dry bottle. This International Standard specifies a method for the determi- nation of the arsenic content of fruits, vegetables and derived The platinized zinc thus prepared shall be submitted to the preliminary test (see 6.1.1). products. NOTE - Non-platinized zinc granules may be used if the product is shown to be suitable by the preliminary test. 2 Reference 4.5 Potassium hydroxide, in pellets ISO5515,Fruits,vegetablesandderivedproducts Decom position of organic matter prior to analysis -- Wet method. 4.6 Tin(ll) chloride solution, prepared as follows. Carry out a cold attack on 20 g of pure granulated tin with 3Principle 100 ml of concentrated hydrochloric acid (020 = 1,19 g/ml). Decomposition of a test portion, reduction of arsenic(V) to Store in the presence of metallic tin, protected from air, in a arsenic(ll) with tin(l) chloride and transformation of the bottle provided with a security device (to avoid overpressures arsenic into arsine by the action of nascent hydrogen. Forma- caused by the liberation of hydrogen). tion of a red coloured complex by the action of the arsine on silver diethyldithiocarbamate and spectrophotometric measure- 4.7 Potassium iodide, 100 g/l solution. ment at a wavelength of 520 nm. 4.8 Sodium hydroxide, standard volumetric solution, c(NaOH) = 1 mol/l. Reagents 4 4.9 Arsenic, standard solution corresponding to 10 mg of All reagents shall be of recognized analytical purity and shall, in arsenic(V) per litre, prepared as follows. particular, be free from arsenic [with the exception of the stan- dard arse