SOLID-PHASE BUTYLATION AND VAPORIZATION FOR DETERMINATION OF LEAD BY HEATED QUARTZ CELL ATOMIC-ABSORPTION SPECTROMETRY

For electrothermal sample introduction, a tungsten boat furnace (TBF) atomizer was transformed to an organometal generator for heated quartz cell (HQC) atomic absorption spectrometry. Inorganic lead(II) was converted to butyllead species, possibly tetrabutyllead, by a thermochemical reaction with a Grignard reagent. It instantly vaporized and was then introduced into the HQC. Utilizing an exchangeable small sample cuvette placed on the TBF for the reaction was very favorable from the viewpoints of easy handling, no memory effect, and keeping stable furnace conditions. Since the analyte was vaporized at a comparatively low temperature (800 degrees C), essentially no interference from most foreign ions was observed. The calibration graph was linear up to 0.3 mg dm(-3) of lead and the limit of detection (2S/N) was 7 mu g dm(-3) of lead when 100 mm(3) of an aqueous solution was loaded on the cuvette. The relative standard deviation (0.2 mg dm(-3) of lead, n=6) was 2.0%. Analytical results for some environmental samples are presented.