Direct determination of inorganic mercury in biological materials after alkali digestion and amalgamation

Abstract

A reliable method is described for the determination of inorganic mercury in biological materials in the presence of organic mercury. This is principally based on the fact that hydrogen peroxide oxidatively liberates inorganic mercury from organic substances in strong alkali and reduces it to the metallic state without decomposing organic mercurials concomitantly present. The metallic mercury, vaporised with a nitrogen stream, is trapped by gold amalgamation and then released for electrothermal atomisation atomic-absorption spectrometry. The detection limit is 1 ng of inorganic mercury and the co-efficient of variation for 40 ng of inorganic mercury is 2.8%.