1783 NTERNATIONAL STANDARD (Tso INTERNATIONAL ORGANIZATION FOR STANDARDIZATION MEKAYHAPOAHA OPTAHW3ALIMS IO CTAHIAPTH3ALIWH·ORGANISATION INTERNATIONALE DE NORMALISATION Magnesium alloys - Determination of zinc - Volumetric method First edition - 1973-11-01 ISO1783-1973 (E) UDC 669.721.5: 546.47 : 543.24 Ref.No.ISO1783-1973 (E) Descriptors : magnesium alloys, chemical analysis, determination of content, zinc, volumetric analysis. Price based on 3 pages FOREWORD Iso (the International Organization for Standardization) is a worldwide federation of national standards institutes (IsO Member Bodies). The work of developing International 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. Prior to 1972, the results of the work of the Technical Committees were published as Iso Recommendations; these documents are now in the process of being transformed into International Standards. As part of this process, International Standard ISO1783 replaces IS0 Recommendation R1783-1970 drawn up by Technical Committee iSO/TC 79, Light metals and their alloys. The Member Bodies of the following countries approved the Recommendation : Australia Iran South Africa, Rep. of Belgium Israel Spain Canada Italy Sweden Czechoslovakia Korea,Rep.of Switzerland Egypt, Arab Rep. of Netherlands Thailand Germany NewZealand Turkey Greece Norway United Kingdom Hungary Peru U.S.A. India Poland The Member Body of the foilowing country expressed disapproval of the Recommendationontechnicalgrounds: France International Organization for Standardization, 1973 Printed in Switzerland INTERNATIONALSTANDARD ISO1783-1973 (E) Magnesium alloys -- Determination of zinc -- Volumetric method 1SCOPEANDFIELDOFAPPLICATION 3.6 Hydrochloric acid, p approximately 1,01 g/ml, ap- proximately N solution. This International Standard specifies a volumetric method for the determination of zinc in magnesium alloys not Ditute 85 ml of the hydrochloric acid (3.3) with water and containing cadmium. make up the volume to 1 000 ml. This method is applicable to the determination of zinc 3.7 Hydrochloric acid,p approximately1,0 g/mi,approxi content between 0,10 and 8,0 %. mately0,005N solution. Dilute 5 ml of the hydrochioric acid (3.6) with water and 2 PRINCIPLE make up the volume to 1 000 ml. Hydrochloric acid attack and elimination of the excess of 3.8Nitric acid,papproximately1,4g/ml,approximately acidbyevaporation. Taking up of the residue in 67% (m/m) solution or 15 N. hydrochloric acid solution (2 N) and passage of the solution through a strongly basic anion exchange resin. 3.9Ammonia,p approximately 0,90 g/ml, approximately Elution of the zinc absorbed on the resin with hydrochloric 28 % (m/m) solution or 14 N. acid solution (0,005 N). Titration of the zinc by EDTA standard solution using 3.10 Acetic acid, p approximately 1,007 g/ml, approxi- dithizone indicator. mately N solution. Dilute 58 ml of glacial acetic acid (p approximately 1,05 g/ml), approximately 17,4N solution, with water and 3REAGENTS make up the volume to 1 000 mi. During the analysis use only distilled water or water of 3.11 Ammonium acetate, 500 g/l solution. equivalent purity. Dissolve50gofammoniumacetate(CHCOONH4)in 3.1Strongly basicanion exchange resin, either waterandmakeupthevolumeto100ml. heteroporous or isoporous, of the polystyrene type with quaternary ammonium groups (for example Dowex 1 X 2, De-Acidite FF SRA 62 or equivalent) in the chloride form, 3.12 Zinc, standard solution containing 2 g of zinc per containing from 2 to 3% cross linking (expressed as .a litre. percentage