Rapid chelatometric determination of samarium and aluminium in the same solution and at the same pH after masking and demasking of aluminium with acetylacetone

A simple stepwise complexometric method with EDTA has been developed for the determination of samarium and aluminium in a single aliquot solution involving direct titration of Sm (III) at pH 5.3 and indirect titration of Al (III) at the same pH using xylenol orange as an indicator. Samarium is determined by direct titration with EDTA after masking aluminium with acetylacetone (at −20°C). Aluminium is determined indirectly with EDTA after demasking of aluminium with acetylacetonate at 90°C. Interferences due to Ti, Zr, Mn, Ni, Co, Cu etc have been eliminated. The method has been standardized against synthetic solutions and applied to various glasses.