DIRECT DETERMINATION OF LEAD IN WHOLE HUMAN BLOOD BY TOTAL REFLECTION X-RAY-FLUORESCENCE SPECTROMETRY

A new and fast sample preparation technique was developed for the analysis of lead in whole human blood by total reflection X-ray fluorescence spectrometry. A 2-mu-l drop of fresh blood was pipetted onto a quartz glass reflector, dried and ashed in a low-temperature oxygen plasma asher operated at 50 mW for 18 minutes. The residue, consisting mainly of metals and being free of low Z elements, was exposed to an X-ray beam coming from a total reflection system with a cut-off reflector. This system gives a significant background reduction. The detection limit achieved for Pb is about 0.03-mu-g/ml for 1000 s measuring time. Whole blood samples were obtained from donors occupationally exposed to lead contamination in a car battery factory and from unexposed donors. Blood lead concentrations found in these individuals are reported.