INVESTIGATION OF THALLIUM HYDRIDE GENERATION USING IN-SITU TRAPPING IN GRAPHITE TUBE BY ATOMIC-ABSORPTION SPECTROMETRY

Thallium hydride was generated from aqueous solutions by merging sampl e and sodium tetrahydroborate reductant in a batch system. In situ pre concentration of volatile thallium hydride in a preheated graphite fur nace coated with palladium, which was used as both the collection medi um and atomizer, greatly improved the sensitivity for the determinatio n of thallium by hydride generation atomic absorption spectrometry. Th e presence of tellurium can increase the generation efficiency of thal lium hydride. The operating conditions were optimized. The calibration graph is linear up to 100 ng and the characteristic mass for thallium was 0.92 ng which is seventeen times lower than that obtained with th e heated quartz tube atomizer. (C) 1998 Elsevier Science B.V.