A simplified determination of urinary cadmium, lead and thallium with use of carbon rod atomization and atomic absorption spectrometry. Clin. Chem

Lead, cadmium, and thallium are determined in a single 3-mI urine sample. The three metals, simulta-neously chelated with sodium diethyldithiocarba-mate, are extracted (at pH 3-7) into methyl isobutyl ketone (isopropylacetone), and the carbon rod atom-izer, in conjunction with atomic absorption spectro-photometry, is used to analyze the extracts. Small sample requirements (1.6.tl) permit the extraction to be carried out in small-volume disposable glass-ware, with use of disposable pipets. Within-run coeff i-cients of variation were all less than 5%; recovery ranged from 96-106%. Several normal urinary con-stituents, added in excess, negligibly affected recov-eries. Ethylenediaminetetraacetate in the urine inhib-ited recovery of lead; this was reversed by addin