The procedure for the preparation of a principal solution for chemical analysis requires at first an alkaline fusion of the test portion, either with a mixture of sodium carbonate and boric acid or with a mixture of sodium carbonate and sodium tetraborate. Subsequent dissolution of the molten mass in an excess of nitric acid and adjustment of an appropriate aliquot portion to pH 2. Replaces ISO Recommendation R804/1968.
Status : WithdrawnPublication date : 1976-09
Edition : 1Number of pages : 3
Technical Committee:Materials for the production of primary aluminium