714 NTERNATIONAL STANDARD ISO Zinc --- Determination of iron content - Photometric method Zinc -- Dosage du fer -- Methode photométrique First edition - 1975-07-15 ISO 714-1975 (E) UDC 669.5 : 543.4 : 669.12 Ref. No. 1SO 714-1975 (E) Descriptors : zinc, chemical analysis, determination of content, iron, photometric analysis. Price based on 2 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 International Standards is carried out through ISsO 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. Internationai organizations, governmental and non-governmental, in liaison with IsO, also take part in the work. Draft International Standards adopted by the Technica! 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 Technicai Committees were published as IsO Recommendations; these documents are now in the process of being Committee ISO/Tc 18 has reviewed ISO Recommendation R 714 and found it technically suitable for transformation. International Standard Iso 714 therefore ISO Recommendation R 714 was approved by the Member Bodies of the following countries : Hungary South Africa, Rep. of Australia Belgium India Spain Switzerland Brazil Ireland Canada Israel Thailand Chile Italy Turkey United Kingdom Czechoslovakia Korea, Rep. of Egypt, Arab Rep. of Korea, D.P. Rep. of U.S.A. New Zealand France U.S.S.R. Germany Norway Yugoslavia The Member Body of the following country expressed disapproval of the Recommendation on technical grounds : Japan Body disapproved the transformation of ISO/R 714 into an No Member International Standard. @ International Organization for Standardization, 1975 Printed in Switzerland Copyright International Organization for Standardization Notfor Resa ISO 714-1975 (E) INTERNATIONAL STANDARD Zinc -- Determination of iron content -- Photometric method 1 SCOPE AND FIELD OF APPLICATION 4.6 Iron, standard solution. This International Standard specifies a photometric method Weigh 0,250 g of pure iron to the nearest 0,001 g and for the determination of the iron content of zinc. attack with a few millilitres of hydrochloric acid (4.2). Oxidize with a few drops of hydrogen peroxide (4.3). The method is applicable to the types of zinc defined in Decompose the excess hydrogen peroxide by boiling. Cool. ISO/R 752, provided that the copper content does not Transfer quantitatively to a 1 1 volumetric flask. Dilute to exceed 0,01 % the mark and mix. Transfer 100 ml of this solution to a 500 ml volumetric flask. Dilute to the mark and mix. It is suitable for the determination of iron contents between 0,001 and 0,1 %. 1 ml of this solution contains 0,050 mg of iron. 2 REFERENCES 5 APPARATUS ISO/R 752, Zinc ingots. Ordinary laboratory apparatus and IsO 3751, Zinc ingots -- Selection and preparation of 5.1 Photometer, wavelength 425 nm, and 1 cm cells.2) samples for chemical analysis. 1) 6 SAMPLING 3 PRINCIPLE Sampling shall be carried out in accordance with the Photometric determination of the yellow colour of the requirements of ISO 3751. formed in an sulphosalicylic acid ferriccomplex ammoniacal solution. 7 PROCEDURE 4 REAGENTS 7.1 Test portion During the analysis, use only reagents of analytical reagent Weigh 10 g of the test sample to the nearest 0,01 g. grade and distilled or demineralized water. 7.2 Blank test 4.1 Ammonia solution, p 0,91 g/ml. Simultaneously with the actual determination, carry out a 4.2 Hydrochloric acid, p 1,19 g/ml. blank test using the same quantities of each reagent and following the same procedure. 4.3 Hydrogen peroxide, 30 % (m/m) H202. 7.3 Plotting of the calibration cur