Determination of triethyllead, diethyllead and inorganic lead in urine by atomic absorption spectrometry.

Abstract

A method was developed for the sequential extraction of tetraethyllead (Et4Pb), triethyllead (Et3Pb+), diethyllead (Et2Pb2+) and inorganic lead (Pb2+) from one urine sample with methyl isobutyl ketone and the subsequent sequential determination of the respective species of lead by flame and flameless atomic absorption spectrometry. When 40 ml of a urine sample to which 2 μg of Pb of each of Et4Pb, Et3Pb+, Et2Pb2+ or Pb2+ had been experimentally added was assayed for the respective species of lead by flame atomic absorption spectrometry, ten repetitions of the assay gave a mean recovery rate of 98% for each of Et4Pb, Et3Pb+, and Et2Pb2+, and 99% for Pb2+, with a coefficient of variation of 2.0% for Et4Pb, 0.7% for Et3Pb+ and Pb2+, 2.6% for Et2Pb2+, and a detection limit of 4 μg of Pb/L for Et4Pb, 3 μg of Pb/L for Et3Pb+, and 5 μg of Pb/L for each of Et2Pb2+ and Pb2+. Examination of urine samples from a patient with tetraethyllead poisoning 22 days after exposure to the lead revealed that the total lead output was made up of about 51% Pb2+, about 43% Et2Pb2+, and about 6% Et3Pb+ but no Et4Pb. Administration of calcium ethylenediaminetetraacetic acid (Ca-EDTA) was followed by no increased urinary excretion of Et3Pb+ or Et2Pb2+.