Analysis of Geological Materials for Bismuth, Antimony, Selenium and Tellurium by Continuous Flow Hydride Generation Inductively Coupled Plasma Mass Spectrometry

A novel introduction system for hydride generation-inductively coupled plasma mass spectrometry: determination of selenium in biological materials

“…In addition to elements such as In, 36 Tl 37 and Pb, 38 which are known to form volatile hydrides, or Hg which forms a cold vapour, these additional elements show promising sensitivity and precision under the tested conditions. This can only be rationalised by their formation of volatile species through reaction with NaBH 4 . In an attempt to exclude the possibility that the observed signals were caused by a ®ne aerosol fraction transported to the ICP, the contribution from such an aerosol was measured separately by replacing the NaBH 4 with 1 M HCl.…”

“…10 Additionally, various chelating ligands have been used as masking agents, 7,9,11,12,14 amongst other techniques, 15 in an effort to prevent the interfering metals from being reduced. Although separation of the analyte from the matrix prior to hydride generation can resolve the problem, and methods based on ion exchange 16 or coprecipitation 4 have been employed, this requires additional sample preparation. Optimising the generation conditions with special regard to the kinetics of the reaction may be used to minimise suppression effects, since Se is reduced faster than the interfering metals.…”

“…Optimising the generation conditions with special regard to the kinetics of the reaction may be used to minimise suppression effects, since Se is reduced faster than the interfering metals. 16± 20 A successful approach based on this has been demonstrated using a moving bed reactor, 21 wherein the liquid sample is dropped onto immobilised KBH 4 and the volatile products immediately removed from the reaction surface by a¯ow of gas. Although interference from the presence of Zn and Fe was reduced, severe effects remained from the presence of Au, Pt, Pd, Co and Ni.…”

“…10,13 Several approaches have been taken in an effort to overcome this effect. In general, signal suppression can be reduced by decreasing the concentration of NaBH 4 and by increasing the concentration of HCl. 10 Additionally, various chelating ligands have been used as masking agents, 7,9,11,12,14 amongst other techniques, 15 in an effort to prevent the interfering metals from being reduced.…”

“…Signal intensities for all four analytes generated using 0.5% (m/v) NaBH 4 (containing 0.05% NaOH) were approximately 60% of those obtained with 1% (m/v). When 5% (m/v) NaBH 4 (containing 0.1% NaOH) was used, response for As, Se, Sn and Sb was reduced to 35, 10, 65 and 65%, respectively, of their optimal values achieved with 1% (m/v) NaBH 4 . Although lower reagent concentrations may be favourable for minimisation of potential interferences from transition metals, 10 the short reaction time used here is not conducive to optimum response.…”