Rapid determination of mercury, copper and zinc in hair by oxygen-flask combustion method.

Abstract

An oxygen-flask combustion of hair replaces wet ashing prior to the determination of mercury, copper and zinc. After 0.5 g of hair has been burned in an oxygen-filled flask, of 1, 000 ml capacity, the metals are absorbed in 2.5 N sulfuric acid solution. Then, the metals of lower oxidation state in the absorbing solution were oxidized with potassium permanganate. The mercury was determined spectrophotometrically with dithizone by a slight modification of Ukita's method. Interference from zinc, disregarded by other workers, has been studied and excluded by masking with EDTA. The copper and zinc was determined spectrophotometrically with dithizone and sodium diethyldithiocarbamate, respectively. The mercury of 1 ppm or above in hair could be determined with a variation coefficient about 3%, and the relative experimental error was nearly 5% in the presence of 145279 ppm of copper and 84250 ppm of zinc.