DETERMINATION OF LEAD(II) BY ELECTROTHERMAL ATOMIZATION ATOMIC-ABSORPTION SPECTROMETRY AFTER COPRECIPITATION WITH GALLIUM(III) PHOSPHATE

Gallium(III) phosphate coprecipitates quantitatively 0.1-2.0 mu g of l ead(II) from 100-500 cm(3) of a sample solution at pH 2.5-6.0. The cop recipitated lead(II) can be sensitively determined by electrothermal a tomization atomic absorption spectrometry without any influence of gal lium(III) phosphate. The calibration curve is linear from 4 to 80 ng c m(-3) for lead(II). The detection limit (signal/noise = 2) is 0.095 ng cm(-3) of lead(II) in 500 cm(3) of the initial sample Solution. Thirt y-four diverse ions tested did not interfere seriously with the determ ination of lead(II). This method was successfully applied to the deter mination of lead(II) in tap and river water.