2830 NTERNATIONAL STANDARD (Tso) INTERNATIONAL ORGANIZATION FOR STANDARDIZATION·MEKIYHAPOAHA OPIAHM3ALMH TIO CTAHIAPTH3ALIHM·ORGANISATION INTERNATIONALE DE NORMALISATION Cryolite, natural and artificial - Determination of aluminium content --- Atomic absorption method First edition -- 1973-12-15 Asl lnternt Doc sect UDC 661.8 : 553.634 : 546.621 : 543.42 Ref. No. ISO 2830-1973 (E) Descriptors : cryolite, chemical analysis, determination of content, aluminium, photometry, atomic absorption 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 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. Internationai organizations, governmental and non-governmental, in liaison with iso, aiso 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 2830 was drawn up by Technical Committee ISO/TC 47, Chemistry, and circulated to the Member Bodies in July 1972. It has been approved by the Member Bodies of the following countries : Australia India South Africa, Rep. of Austria Ireland Sweden Belgium Switzerland Israel Canada Thailand Italy Czechoslovakia Mexico Turkey Egypt, Arab Rep. of Netheriands United Kingdom France Poland U.S.S.R. Germany Portugal Hungary Romania This International Standard has aiso been approved by the International Union of Pure and Applied Chemistry (IUPAC). The Member Body of the following country expressed disapproval of the document on technical grounds : New Zealand @ International Organization for Standardization, 1973 . Printed in Switzerland Copyright International Organization for Standardization Not for Resale ISO 2830-1973 (E) INTERNATIONAL STANDARD Cryolite, natural and artificial -- Determination of aluminium content --- Atomic absorption method 1 SCOPE 5.4 Aluminium, standard solution, corresponding to 1,00 g of Al per litre. This International Standard specifies a flame atomic Pickle 1,5 g of extra pure aluminium (99,999 % purity), in absorption method for the determination of the aluminium content of natural and artificial cryolite. the form of shavings obtained by milling or drilling, in a little nitric acid, p approximately 1,40 g/ml, about 68 % (m/m) solution. 2 FIELD OF APPLICATION Wash the pickled shavings with water and then dry them The method is applicable to the determination of by washing with acetone. Weigh, to the nearest 0,000 1 g, aluminium in natural and artificial cryolite of normal 1,000 g of the dried shavings, put them in a tall-form composition for which the molar ratio NaF/AlF3 is equal beaker of suitable capacity (for example, 250 ml) and to about 3. add about 100 ml of water, 5 ml of the hydrochioric acid solution (5.2) and 10 ml of the sulphuric acid solution (5.1). Wait until the reaction subsides, then place the 3 REFERENCE beaker on a sand bath and maintain a gentle heat until al! ISO/R 1619, Cryolite (natural and artificial) - Preparation the aluminium has dissolved. Allow to cool, transfer the solution quantitatively to a 1 000 ml one-mark volumetric and storage of test samples. flask, dilute to the mark and mix. 1 ml of this standard solution contains 1,00 mg of Al. 4 PRINCIPLE Dissolution of a test portion in concentrated sulphuric acid with hydrochloric acid and and treatment water. Atomization of the solution into an acetylene-dinitrogen monoxide flame and determination of the aluminium 6APPARATUS content by photometric measurement of the absorption of Ordinary laboratory apparatus and the 309,3 nm line emitted by an