In-situ trapping arsenic hydride on tungsten coil and comparing interference effect of some hydride forming elements using different types of atomizers

Abstract

Hydride generation atomic absorption spectrometry (HGAAS) with different types of atomizers (flame heated quartz T-tube and W-coil) was evaluated for comparison of interference effects of some hydride forming elements for arsenic determination. W-coil was used as an on-line atomizer or as a trapping surface. Mutual interferences of Sb(III), Se (IV), Sn (II) and Te(IV) on arsenic signal were compared with flame heated quartz T-tube atomizer and W-coil; on-line atomization and in-situ trapping modes. When W-coil was operated at on-line atomization mode the interference magnitudes could not be improved as much as expected with respect to quartz T-tube atomizer. However, decent improvements were achieved for interference magnitudes of each interferent species with in-situ trapping on iridium coated W-coil. Under optimized conditions and using 60s trapping period (sample volume 6ml), the limit of detection was found as 0.03ngml−1 and the calibration was linear in between 0.25–4.0ngml−1 As. The precision of the analytical method was less than 2.5% in terms of RSD (n=11) for 1.0ngml−1 arsenic concentration. The accuracy of the method was tested with certified reference materials; fortified water TMDA 61 (NWRI) and waste water EU-L-1 (SCP). The results were in a good agreement with the certified values at 95% confidence level.