The stability of human blood lead in storage

Whole blood specimens from 12 occupationally exposed workers were stored for 10 weeks either in heparin or EDTA at 22 degrees, 4 degrees, and -20 degrees C for the study of the stability of lead in storage. The lead concentrations of these specimens ranged from 226 to 616 micrograms/L. Polypropylene and vacutainer tubes were used for storage. A Zeeman Graphite Furnace Atomic Absorption Spectrophotometer was used to determine the lead concentration. No loss of lead was found on the 12 specimens stored with heparin or EDTA at three different temperatures in all containers over the 10-week period. The variation of the lead concentration is comparable to the average precision of two quality control specimens, Tox-EL 1 and Tox-EL 2, of 7.4% and 6.1%. The use of the original vacutainer tubes with either heparin or EDTA and refrigerated temperature (4 degrees C) for the storage of human whole blood specimens for routine lead determination is recommended.