EVALUATION OF COLD VAPOR FURNACE ATOMIC NONTHERMAL EXCITATION SPECTROMETRY FOR THE DETERMINATION OF MERCURY IN ENVIRONMENTAL-SAMPLES

Furnace atomic non-thermal excitation spectrometry (FANES) was used to determine Hg following reduction with tin(II) chloride and in situ preconcentration in the graphite tube lined with Pt gauze. Response surface methodology was used to optimize the discharge pressure and current for maximum signal-to-noise ratios. The absolute detection limit under optimum conditions was 20 pg, and the linear calibration range extended to 20 ng, limited by incomplete removal of Hg from the FANES source during one atomization sequence. Three environmental standard reference materials (SRM 1572 "Citrus leaves", SRM 1575 "Pine needles" and SRM 1645 "River sediment") were prepared for analysis by microwave-assisted digestion, and accurate results were obtained for the determination of Hg at the sub mu-g g-1 level using calibration against simple aqueous standards.