4748 International Standard OS1) INTERNATIONAL ORGANIZATION FOR STANDARDIZATION+MEKAYHAPOAHAR OPTAHW3ALWR NO CTAHAAPTW3AUWMORGANISATION INTERNATIONALE DE NORMALISATION Copper alloys - Determination of iron content Na2EDTA titrimetric method Alliages de cuivre-Dosage dufer--Methode titrimetrique auNazEDTA First edition - 1984-04-15 ISO 4748-1984 (E) UDC 669.3. : 543.24 : 546.72 Ref.No.ISO4748-1984(E) Descriptors: copper, copper alloys, chemical analysis, determination of content, iron, volumetric analysis. Price based on 2 pages Foreword Iso (the International Organization for Standardization) is a worldwide federation of national standards bodies (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 authorized 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 4748 was developed by Technical Committee ISO/TC 26, Copper and copper alloys, and was circulated to the member bodies in September1982. It has been approved by the member bodies of the following countries : Belgium iran Spain Brazil Italy Sweden Canada Japan Switzerland China Korea, Dem. P. Rep. of Turkey Czechoslovakia Korea,Rep.of USA Egypt, Arab Rep. of Norway USSR France Poland Venezuela Germany, F.R. Romania The member bodies of'the following countries expressed disapproval of the document on technical grounds : Australia South Africa, Rep. of @InternationalOrganizationforStandardization,1984 Printed in Switzerland ISO 4748-1984 (E) INTERNATIONALSTANDARD Copper alloys - Determination of iron content - NazEDTA titrimetric method Scope and field of application 3.9 Hexamethylenetetramine, solution. This International Standard specifies a titrimetric method for Dissolve 200 g of hexamethylenetetramine in water and dilute the determination of the iron content of copper alloys. to 1 000 ml. The method is applicable to contents of iron in all types of copper alloys listed in International Standards. 3.10 Disodiumethylenediaminetetraacetate dihydrate (NaEDTA),0,05mol/Istandardvolumetricsolution 2Principle Dissolve 18,61 g of Na2EDTA in water, dilute to the mark in a 1 000 ml one-mark volumetric flask, and mix. Standardize the Separation of iron from copper by extraction as the solution by taking a known amount of the iron(lll) solution iron(ll)-chloro complex,followed by chelation with excess (3.12) and, omitting only the extraction step, titrating as in EDTA at pH 4,5 and back-titration with a standard volumetric clause 5. zinc solution. 3.11 Zinc, 0,05 mol/l standard volumetric solution. 3Reagents Dissolve 3,269 g of high purity zinc metal with 25 ml of nitric During the analysis, use only reagents of recognized analytical acid (1 + 1).Expel nitrous oxides byboiling.Cool and adjust to grade and only distilled water or water of equivalent purity. pH 4 to 5 by addition of the hexamethylenetetramine solution (3.9). Dilute to the mark with water in a 1 000 ml one-mark 3.1 Hydrochloric acid, Q 1,19 g/ml. volumetric flask and mix. 3.2 Hydrogen peroxide,30 % (m/m)solution. 3.12 Iron(lll),0,05 mol/I solution. Dissolve 3,992 g of iron(Il) oxide (Fe203) with 40 ml of the 3.3 Methyl isobutyl ketone. hydrochloric acid solution (3.5). Dilute to the mark with water in a 1 000 ml one-mark volumetric flask and mix. 3:4 Ethanol. 3.13 Xylenol orange. 3.5 Hydrochloric acid, diluted 1+ 1. Grind 1 g of xylenol orange with 100 g of potassium nitrate. Dilute 100 ml of the hydrochloric acid (3.1) with 100 ml of water. 4Apparatus 3.6 Lithium chloride,solution. Dissolve 275 g of lithium chloride (LiCl) in water and dilute to Ordinary