Accuracy and precision of the determination of mercury in human scalp hair by cold-vapour atomic-absorption spectrophotometry

Abstract

The acid oxidation of hair and the determination of mercury by cold-vapour atomic-absorption spectrophotometry have been investigated. A procedure was developed for the complete oxidation of the hair while mercury losses through evaporation and through adsorption in the walls of the containing vessels are minimised. The coefficient of variation for the method can vary over the range 3–8%. The method has been used to show two novel features: differences between the scalp-hair mercury levels of vegetarians and non-vegetarians and variations in scalp-hair mercury levels within individual scalps and the way in which homogeneous scalp-hair samples can be prepared. Also demonstrated are the substantial differences in scalp-hair mercury levels that can be found among people such as dentists who are occupationally exposed to mercury.