RAPID CHROMITE DISSOLUTION USING A MANGANESE-DIOXIDE LITHIUM-SULFATE SULFURIC-ACID MIXTURE FOR MATRIX-INDEPENDENT DETERMINATION OF CHROMIUM

A mixture of manganese dioxide-lithium sulphate-sulphuric acid has bee n used for accurate and precise estimation of chromium in various chro mite matrices. Inter-method comparison studies show that the proposed procedure can be used for a quality control programme and in the evalu ation of reference materials. The method is very simple and easily ada ptable and involves no separation of the analyte from the matrix eleme nts. Sample decomposition is straight forward (0.2 g of sample + 0.3 g of MnO2 + 1.0 g of Li2SO4 + 10 ml of H2O + 20 ml of 36 M H2SO4).