In situ trapping of antimony hydride on iridium-coated tungsten coil and interference studies

Abstract

A continuous flow hydride generation manifold coupled to a tungsten coil atomizer for in situ trapping of antimony hydride was described. Iridium coated tungsten coil atomizer can be used for both on-line atomization and trapping while bare tungsten coil can be used only for on-line atomization mode. The interference effects of several hydride forming elements such as As(III), Se(IV), Sn(II) and Te(IV) were compared with a flame heated quartz tube atomizer and tungsten coil atomizer; on-line atomization and in situ trapping modes. The analytical figures of merit for antimony hydride using 60 s trapping period and iridium coated tungsten coil were found as; linear range 0.25–5 ng ml−1, characteristic concentration 0.029 ng ml−1, the limit of detection (3s) 0.028 ng ml−1 and the precision in terms of % RSD was between 1–3. The iridium coating was stable for at least 200 firings without sensitivity loss. The accuracy of the method was tested with certified reference materials Fortified Water TMDA 61 (NWRI), Waste Water EU-L-1 (SCP) and Tea sample GBW 07605. The results were found in good agreement with the certified values at 95% confidence level.