Hydride generation atomic absorption spectrometric determination of arsenic, antimony and tin by in situ trapping of their hydride tungsten coil and interference studies

A sensitive method was developed by continuous flow hydride generation manifold coupled to a Ir coated tungsten coil atomizer for in situ trapping of As, Sb, Sn hydride. Coating the W-coil surface by Ir significantly enhances the trapping efficiencies for As, Sb and Sn and the coating was stable at least 200 firings without any sensitivity loss. When 60s trapping period was used (sample volume is 6 ml) LOD (3 ? ) values for As, Sb, Sn were found as 30 pg/ml, 28 pg/ml and 65 pg/ml, respectively. After the analytical conditions have been optimized, the interferences of some hydride forming elements were studied using three atomization modes (W-coil in situ trap, W-coil on-line atomization, quartz tube atomizer) were compared. In order to test the accuracy of the method certified water standard reference materials TMDA 61 (NIWR) and Waste Water EU-L-1 (SCP) were analyzed and the results were found in good agreement with the certified values at 95% confidence level.