Determination of lead by graphite furnace atomic absorption spectrometry with argon-hydrogen as the purge gas using low-temperature atomisation

Abstract

A method is described for the determination of lead in environmental samples by graphite furnace atomic absorption spectrometry with argon-hydrogen as the purge gas using low-temperature atomisation. The addition of hydrogen to argon helps to reduce the interference caused by the matrix in the sample, and a significant enhancement of the peak absorbance was achieved for lead in environmental sample analysis. The suppression of the lead atomic signal for a real sample in argon was probably due to the presence of halide or perchlorate in the sample. The decrease in the level of interference when hydrogen was added to argon may be ascribed to the formation of HCl, which has a relatively high dissociation constant. The analytical results obtained for lead in environmental reference materials indicate that the method is accurate and reliable.