The determination of minute amounts of lead in urine

Abstract

Traces of Pb in urine were detd. following wet oxidation of 50-100 cc. specimens with deleaded H2SO4. Pb was removed from the acid digest as the ether-soluble complex formed with Na diethyldithiocarbamate. After evaporation of the solvent, the residue was converted into PbSO4 by heating with 1 cc. H2SO4 and 4 drops perhydrol. Excess of H2O2 was carefully removed to avoid subsequent oxidation of dithizone. For the detn. as Pb dithizonate, photometric technique was employed with spectrum green filter 604 and neutral grey screen, d. 0.74 as standard. The urinary excretion of a large group of Pb workers varied from 0.1 to 0.35 mg. Pb/1 and 100 cc. duplicate agreed within 0.004 mg.