Stibine and bismuthine trapping in quartz tube atomizers for atomic absorption spectrometry. Part 2: a radiotracer study

A trap-and-atomizer device based on a multiatomizer has been described recently. This compact and universal device enables the preconcentration of As, Sb, Bi and Se hydrides on-line prior to their AAS detection. Up to date only optimization of the method and its analytical applications have been described. In this work, (125)Sb and (205,206)Bi radioactive indicators were used to quantify the efficiency of the individual steps of preconcentration procedure as well as to investigate the spatial distribution of the analytes. The investigation proved the complete trapping and volatilization of Sb and Bi. The trapping efficiency of Sb was better than 93% (RSD<6%) between 200 and 800 degrees C. The trapping efficiency of Bi was above 96% (RSD<5%) between 100 and 800 degrees C whereas it fell to 83% at 900 degrees C. The area of the trapping spot increased with increasing trapping temperature. The trap is capable of trapping up to 400 ng of Bi and 2 mu g of Sb, respectively. Typically, 1-10 ng of analyte is preconcentrated in ultratrace analysis. No change in either trapping efficiency, or in the spatial distribution of analyte was observed with increasing trapped analyte mass. Also the volatilization step proved to be efficient - only (1.8 perpendicular to 1.6)% and (2.9 perpendicular to 0.9)% of original Bi and Sb activity, respectively, was found in the traps after the volatilization at 900 degrees C.