A method was developed for the sequential extraction of tetraethyllead (Et4Pb), triethyllead (Et3Pb
+), diethyllead (Et2Pb2
+) and inorganic lead (Pb
2+) 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 Pb
2+ 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 Et2Pb
2+, and 99% for Pb
2+, with a coefficient of variation of 2.0% for Et4Pb, 0.7% for Et3Pb
+ and Pb
2+, 2.6% for Et2Pb
2+, 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 Et2Pb
2+ and Pb
2+.
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% Pb
2+, about 43% Et2Pb
2+, and about 6% Et3Pb
+ but no Et4Pb. Administration of calcium ethylenediaminetetraacetic acid (Ca-EDTA) was followed by no increased urinary excretion of Et3Pb
+ or Et2Pb
2+.
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