Performance of ICP-MS with Hexapole Collision Cell and Application for Determination of Trace Elements in Bio-Assays

 The application of a hexapole collision cell in quadrupole based inductively coupled plasma mass spectrometry (HEX-ICP-QMS) was studied systematically in order to characterize the performance of this approach for multielement analysis. Additionally, the performance of different solution introduction systems was studied for use with HEX-ICP-QMS (Platform, Micromass Ltd., Manchester, UK) and the developed methods were applied in the multielement analysis of biological tissue. A significant improvement in detection limits was achieved for ions affected by interferences with argon ions and argon-based molecular ions due to the removal of Ar⁺ and ArX⁺ ions (X = H, C, N, O, Ar) as well as for heavy elements (m > 100 u) due to better ion transmission through the hexapole ion guide. Metal oxide ion formation was reduced by up to ten times by the application of hexapole bias potential. Accuracy of the HEX-ICP-QMS measurements was assessed by analyzing standard reference material SRM 1566a Oyster Tissue and comparison with neutron activation analysis. Good agreement of measured trace element concentrations with certified values was found for most elements. Received December 7, 2000. Revision April 3, 2001.