Tin atom formation in a graphite furnace atomizer

Absorbance measurements resolved in time and space are presented for tin vaporized under various conditions in a graphite furnace. Mass spectroscopie studies coupled with temporal and spatial absorbance measurements indicate that oxygen entrained in the inert sheath gas significantly attenuates the free atomic tin population through the rapid formation of SnO. Addition of 10% hydrogen to the sheath gas and enclosure of the atomizer, substantially reduce the effect of entrained oxygen. Similar release mechanisms are postulated with and without hydrogen, but it is suggested that the concentration of elemental tin on the surface at the time of vaporization is greater when hydrogen is included. The effects of added sulfate salts were also studied and it was concluded that the formation and prevolatilization of SnS is responsible for the extreme depressions reported in the literature.