Electrochemical Generation of Lead Volatile Species as a Method of Sample Introduction for Lead Determination by Atomic Absorption Spectrometry

An electrochemical lead volatile species generation system, as a means for sample introduction into a flame atomic absorption spectrometer, has been developed and evaluated for the determination of lead in urine samples. The reaction cell, designed and manufactured in our laboratory, consists of a reaction compartment housing a reticulated glassy carbon cathode and a platinum wire anode. The cell can easily be coupled to the spectrometer via a gas-liquid separator. The characteristic of the cathode material, the volatile species generation efficiency and the possible interferences of some concomitants have been studied. Calculated detection limit based on the variability of a blank solution (3 s(b) criterion) for ten measurements was 11 mu g L-1 and the sensitivity determined from the slope of the calibration graph, was 0.152 L mg(-1). The reproducibility (RSD) for ten replicate measurements at 1.0 mg L-1 lead level, was 1.4%. The accuracy of the method was determined through the analysis of spike urine samples. Recovery of 103.71% +/- 0.05 was achieved.