The determination of zinc in crystalline insulin and in certain insulin preparations by atomic-absorption spectroscopy

Abstract

Atomic-absorption spectroscopy is an excellent technique for the determination of the purity and activity of crystalline and protamine zinc insulins and has been found suitable for the determination of down to 5 µg of zinc. The procedure is rapid and direct as preparation involves only weighing and dissolution of the sample. The method has been applied to the determination of zinc in crystalline and protamine insulin samples. The values obtained for zinc compare favourably with those obtained by the dithizone colorimetric method.