Influence of Na, K, Ca and Mg on lead atomization by tungsten coil atomic absorption spectrometry

The atomization of lead in an electrothermal tungsten coil atomizer in the presence and absence of Na+, K+, Ca2+ and Mg2+ was investigated with the objective of understanding the interference processes. The lead atomization was less affected by Ca2+ and Mg2+ than by Na+ and K+. In the absence of concomitants, lead atomization efficiency was improved by the presence of H-2 (10% v/v) in the purge gas composition, during pyrolysis and atomization steps. The interference caused by Na+ and Ca2+ was negligible when the pyrolysis step was accomplished without H-2 in the purge gas composition The results showed that Na+, K+, Ca2+ and Mg2+ are directly involved in competition reactions for H-2 in condensed phase.