OPTIMIZATION OF ATOMIZATION PARAMETERS IN THE SPECIATION OF ORGANOTINCOMPOUNDS BY HYDRIDE GENERATION GAS-CHROMATOGRAPHY ELECTROTHERMAL ATOMIC-ABSORPTION SPECTROMETRY

The detection of organotin hydrides bg electrothermal (quartz furnace) atomic absorption spectrometry coupled on-line with hydride generatio n is closely dependent on several parameters such as the geometry of t he quartz cell and the flow rates of additive gases, The influence of the design of the atomizer and the effects of the gas flow rates were evaluated in this study. The design of the quartz cell atomizer is not critical provided that a few rules are followed: the helium flow carr ying organotin hydrides should be mixed with hydrogen in as small as p ossible dead volume (no mixing chamber) and oxygen introduction should be made as close as possible to the light path, The ratios of gas flo w rates must be optimized for each cell design, the most important bei ng the H-2:O-2 ratio chosen to produce highly reducing working conditi ons, Detection limits obtained after optimization ranged from 30 to 13 0 pg depending on the conditions and species.