4194 OSI) International Standard INTERNATIONAL ORGANIZATION FOR STANDARDIZATION MEXAYHAPOAHAA OPFAHW3AUUR nO CTAHAAPTM3ALWV·ORGANISATION INTERNATIONALE DE NORMALISATION Magnesium alloys -- Determination of zinc content - Flame atomic absorption spectrometric method Alliages de magnésium - Dosage du zinc - Méthode par spectrométrie d'absorption atomique dans la flamme First edition -- 1981-12-01 U DC 669.71.5 : 543.422 : 546.47 Ref. No. ISO 4194-1981 (E) ISO 4194-1981 (E) Descriptors : magnesium alloys, chemical analysis, determination of content, zinc, atomic absorption spectroscopic method. Price based on 3 pages Copyright International Organization for Standardization Not for Resale 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 ISO 4194 was developed by Technical Committee 1ISO/TC 79, Light metals and their alloys, and was circulated to the member bodies in December 1980. Germany, F. R. South Africa, Rep. of Australia Hungary Spain Austria Brazil India Sweden Canada Italy Switzerland China Japan United Kingdom USA Czechoslovakia Korea, Rep. of USSR Egypt, Arab Rep. of Poland France Romania The member body of the following country expressed disapproval of the document on technical grounds : Netherlands International Organization for Standardization, 1981 Printed in Switzerland Copyright International Organization for Standardization Notfor Resa ISO 4194-1981 (E) INTERNATIONAL STANDARD Magnesium alloys -- Determination of zinc content Flame atomic absorption spectrometric method 1 Scope and field of application 3.6 Zinc, standard solution corresponding to 1 g of Zn per litre. This International Standard specifies a flame atomic absorption Prepare this standard solution by one of the following spectrometric method for the determination of the zinc content of magnesium alloys. methods : The method is applicable to products having zinc (Zn) contents 3.6.1 Weigh, to the nearest 0,1 mg, 1 g of extra pure zinc between 0,1 and 6 % (m/ m). (purity ≥99,99 %), transfer it to a 400 ml beaker and cover with a watch glass. Add, in smatl portions, 25 ml of the hydrochloric acid solution (3.2) and heat gently, if necessary, to complete the dissotution. After cooling, quantitatively transfer it to a 1 000 ml volumetric flask, dilute to the mark and mix. 2 Principle 1 ml of this solution contains 1 mg of zinc. Dissolution of a test portion in hydrochloric acid solution in the presence of hydrogen peroxide and hydrofluoric acid. Aspir- 3.6.2 Weigh, to the nearest 0,1 mg, 1,26 g of zinc oxide ation of the solution into an air-acetylene flame and comparison (ZnO), previously calcinated at 1 000 oC for 1 h and cooled in a of the absorbance of resonance energy of zinc by the test solu- desiccator. Transfer it to a 400 ml beaker, and dissolve it in tion (wavelength of 213,9 nm normaliy) with that of standard 25 mi of the hydrochioric acid solution (3.2). Dilute the solu- solutions. tion, quantitatively transfer it to a 1 000 m! volumetric flask, dilute to the mark and mix. 1 ml of this solution contains 1 mg of zinc. 3 Reagents 3.7 Zinc, standard solution corresponding to o,o50 g of Zn per litre. During the analysis, use only reagents of recognized analytical grade and distilled or deionized water. Transfer 50,0 ml of the standard zinc solution (3.6) to a 1 000 ml volumetric flask, dilute to the m