Custom-made interface between electrothermal vaporiser and inductively coupled plasma-mass spectrometer: Determination of nickel by isotope dilution in plant samples

ICP-mass spectrometer Perkin Elmer Elan 6000 was adapted for ETV analysis b y coupling with GBC GF 3000 graphite furnace atomiser. Both instruments wer e connected by a 25 cm long PTFE tubing of 6 mm. i.d. and a custom-made int erface. The apparatus was applied to nickel determination using isotope dil ution technique. The efficiency of analyte transfer through the interface w as approximately 20%, however the incomplete transfer did not influence the blank values. Measured isotope ratio was very stable, whereas the magnitud e of ion signal showed a little shift. CRM samples were analysed after micr owave decomposition and by slurry technique as well. Obtained results were compared with those of pneumatic sample nebulisation after nickel separatio n on Chelex column. All tested techniques gave accurate results with compar able precision. However, the slurry technique allowed significant decreasin g of the blank values and the limit of detection. The duration of analysis run can also be substantially shortened from several hours to a few minutes . (C) 2001 Published by Elsevier Science B.V.