Extraction and determination of zinc in pharmaceutical samples

A systematic study of extraction of zinc salicylate is reported. Optimum conditions for the extraction and determination of zinc are evaluated from a critical study of the effect of pH, sodium salicylate concentration and triphenylphosphine oxide concentration. The effect of foreign ions on the extraction is also discussed. The probable composition of the species has been deduced from the extraction data. The method has been used to separate zinc from cadmium and mercury in binary mixtures and for the determination of zinc in various pharmaceutical products.