ELECTROTHERMAL ATOMIC-ABSORPTION SPECTROMETRIC DETERMINATION OF ANTIMONY IN METAL CHLORIDE MATRICES USING PROBE AND TUBE-WALL ATOMIZATION

Two atomization modes were used in the determination of antimony by electrothermal atomic absorption spectrometry, namely tube-wall and probe atomization. The reciprocal sensitivity of the tube-wall atomization was approximately twice that of probe atomization when the peak height measurement was used. The interfering effects of different metal chlorides on the determination of antimony were investigated using both atomization modes. The results showed that probe atomization is useful when antimony is determined in samples containing alkali and alkaline earth metal chlorides (especially MgCl2 and CaCl2). Severe background over-compensation interferences were noticed with the deuterium background correction system used when antimony was determined in matrices containing iron and cobalt. To a lesser extent, over-compensation interference was also noticed with nickel. The over-compensation interferences were avoided when 30 mug of magnesium as chemical modifier and a slit-width of 0.2 nm were used in the determinations.