A rapid method for estimating mercury in undigested biological samples.

Magos, L., and Cernik, A. A. (1969). Brit. J. industr. Med., 26, 144-149. A rapid method for estimating mercury in undigested biological samples. A method has been developed for estimating mercury in biological samples using an ultraviolet mercury detector, after liberating the mercury from the urine and other biological samples by a simple chemical method. The overall time for one estimation is less than two minutes, and no special skills are required to operate the technique. The principle of the method is that stannous chloride at high pH liberates mercury from sulphhydryl bonds and converts the liberated mercury into volatile metallic mercury which is subsequently estimated by an ultraviolet photometer. Stannous chloride is added to the acidified sample, and the presence of extra cysteine ensures that no appreciable amount of mercury is lost before the reaction is triggered by the addition of excess sodium hydroxide. The standard solution of mercury developed is stable for months and behaves in the reaction like urine, and, because of its stability, the instrument can be standardized with it frequently and conveniently.