VAPORIZATION MECHANISMS FOR GOLD AND FOR GOLD IN THE PRESENCE OF VANADIUM IN A GRAPHITE ATOMIZER

Time resolved absorbance profiles, the influence of gold concentration and the effect of vanadyl chloride have been established for graphite furnace atomic absorption signals of gold. Conventional furnace operating procedures with both wall and platform atomization modes showed similar results for the orders of reaction, but a few differences were noted in the activation energy values. On account of both the relatively narrow half widths and uniform peak profiles, gold-graphite interactions appear to be very strong for low gold concentrations, where the order of gold release is near to unity. However, gold-graphite interactions decrease for higher concentrations of gold, where the order of gold release deviates from unity. Absorbance profiles were found to be sensitive to the mass of the vanadium present showing larger integrated absorbances when the vanadium mass increases.