Measurement of Total Mercury in BiologicalSpecimens by Cold Vapor Atomic

An ultrasensitive methodfor determiningtotal mercury con-centrations in biological specimens is a prerequisite for monitoringexposureto chroniclow-dose levelsof Hg vapor such as those from dental silver amalgam fillings. The clinicalconsequences of such doses are currently in ques-tion. We describe an adaptation of a two-stagegold amal-gamation preconcentrationstep combined with cold vapor atomic fluorescence spectrometricdetectionfor Hg. At Hg concentrationsof 40 and 350 nmol/L, the within-dayassay CVs were 5 % and 3%, respectively; between-day assay CVs were 8 % and 5%, respectively.Accuracy, as demon-strated by analytical recovery, ranged from 98 % to 105%. The detection limit for the assay is 50 pmollL, which is suitable for measuring total Hg concentrations in speci-mens of human urine, blood, and breast milk, and in mon