Abstract
Direct analysis of organotin compounds by graphite furnace atomic absorption (GFAA) spectrometry is complicated by the presence of chemical interferences that cause a species-dependent sensitivity. To reduce these interferences and optimize GFAA atomization efficiency for organotin analysis, we have (1) coated the graphite atomizer with salt solutions of refractory metals Zr, W, Mo, V and/or with pyrolytic graphite, (2) altered the solution matrix with varying concentrations of NHO(,3) and (3) added Ni as a matrix modifier. The use of Zr-treated cuvettes showed the greatest enhancement in sensitivity ((GREATERTHEQ) 3-fold). An improvement of ca. 5-fold in signal precision and cuvette lifetime were also observed. The other method employed, however, did not appreciably reduce chemical interferences. A study of the transient tin absorption signal and of the cuvette surface structure was undertaken to characterize any resulting effects on the atomization efficiency. The results indicated that the surface of the graphite atomizer is chemically non-uniform and reactive and it directly affects the atomization mechanisms of organotin compounds. We have also evaluated the potential application of GFAA as an element specific detector for high performance liquid chromatography (HPLC) in trace-level speciation of organotin compounds. The retention data, obtained from the HPLC-GFAA analysis of several aryltins and their mixture, are used to develop an empirical correlation between reported toxicity and chromatographic retention.
Harrison, Gabrielle Vuon (1982). Graphite furnace atomic absorption analysis of organotin compounds. Texas A&M University. Texas A&M University. Libraries. Available electronically from
https : / /hdl .handle .net /1969 .1 /DISSERTATIONS -365306.