Use of the carbon rod atomizer for analysis of lead in blood: three methods compared

Measurement of lead in whole blood by use of the carbon rod atomizer and atomic absorption spectrophotometry was investigated for three methods: (a) a simple dilution (one volume of whole blood to two volumes of surfactant solution; (b) direct analysis of whole blood (no sample preparation); and (c) a standard chelation extraction procedure in which sodium diethyldithiocarbamate and methyl isobutyl ketone (isopropylacetone) are used. Within-run precision data for normal and above-normal pools favored the Triton dilution method, for which coefficients of variation were less than 5%. Recoveries of added lead ranged from 94-107% for all three methods. We saw no change in the standard curves for any of the procedures on addition of ethylenediaminetetraacetate to samples. The method of additions was necessary to prepare standards of a matrix composition identical to that of the unknowns.