NTERNATIONAL STANDARD SO) 3220 INTERNATIONAL ORGANIZATION FOR STANDARDIZATION MEKIYHAPOAHA OPTAHI3AIM HO CTAHIAPTW3ALIMM.ORGANISATION INTERNATIONALE DE NORMALISATION Copper and copper alloys - Determination of arsenic - Photometric method Cuivreetalliagesdecuivre--Dosagede/'arsenic--Méthodephotometrique First edition -- 1975-07-01 ISO 3220-1975 (E) UDC 669.3 : 546.19 Ref. No. ISO 3220-1975 (E) Descriptors : copper, copper alloys, chemical analysis, determination of conten arsenic,spectrophotometricanalysis. Price based on 2 pages Copyright International Organization for Standardization Not for Re 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. International Standard ISO 3220 was drawn up by Technical Committee ISO/Tc 26, Copper and copper alloys, and circulated to the Member Bodies in June 1973. It has been approved by the Member Bodies of the following countries : Australia Germany Sweden Austria Ireland Switzerland Belgium Japan Thailand Bulgaria Mexico Turkey Canada New Zealand United Kingdom Norway Chile U.S.A. Egypt, Arab Rep. of Poland Yugoslavia Finland Romania France South Africa, Rep. of No Member Body expressed disapproval of the document. Printed in Switzerland ISO 3220-1975 (E) INTERNATIONAL STANDARD Copper and copper alloys - Determination of arsenic - Photometric method 1 SCOPEANDFIELD OFAPPLICATION 3.8 Ascorbic acid solution. This International Standard specifies a photometric method Dissolve 2 g of ascorbic acid in 100 m! of water; use freshly for the determination of arsenic in copper and copper prepared solutions. alloys. 3.9 Hydrogen peroxide, 30 % (m/m) solution. The method is applicable for the determination of arsenic as an alloying element or as an impurity in copper and all 3.10 Potassium permanganate, 0,1 N solution. types of copper alloys listed in isO Recommendations or I nternational Standards. 3.11 Molybdate solution. 0,95 gof Dissolve ammonium heptamolybdate. 2 PRINCIPLE [(NH4)gMo-O24.4H20], in 200 ml of the sulphuric acid Extraction of arsenic from a hydrochloric, hydrobromic (3.7); use freshly prepared solutions. and perchloric acid-containing solution using benzene. After re-extraction with water, photometric determination 3.12 Arsenic stock solution. as molybdenum blue. Dissolve 132 mg of arsenious oxide (As203) with 10 ml of Phosphorus and silicon in milligram amounts do not sodium hydroxide, (NaOH), 1 N, in a polyethylene beaker, interfere. add 12,5 ml of hydrochloric acid (HCI), 1 N, and dilute in a 250 ml volumetric flask with water to the mark. 3 REAGENTS 3.13 Arsenic standard solution. All the reagents shall be of analytical' grade. Distilled or Add to 25 mi of the arsenic stock solution (3.12) in a deionized water shall be used. 500 ml volumetric flask 20 ml of the hydrochloric acid (3.6) and dilute with water to the mark. (1 ml is equivalent 3.1 Benzene. to 20 μg of arsenic.) 3.2 Hydrochloric acid p 1,19 g/ml. 4 APPARATUS 3.3 Hydrobromic acid p 1,5 g/ml. 4.1. Normal laboratory apparatus 3.4 Perchloric acid p 1,67 g/ml. 4.2 Photometer. 3.5 Chloric acid. 5 SAMPLING 3.6 Hydrochloric acid, 6 N. Carry out the sampling in accordance with the requirements Dilute 100 m! of hydrochloric acid (p 1,19 g/mi) with of IsO : ..1) 100 ml of water: 6 PROCEDURE 3.7 Sulphuric acid solution. Dilute 95 ml of sulphuric acid (p 1,84 g/ml) with water to Test portion mass for arseni