A hexapole collision cell was investigated for significant reductions of interferences by molecular ions in inductively coupled plasma mass spectrometry (ICPMS) using a direct injection high efficiency nebulizer (DIHEN). Collision induced reactions with hydrogen reduced isobaric interferences while the addition of helium as a collision gas enhanced analyte ion transmission through collisional focusing. Improved figures of merit were obtained for elements (Ca, Fe, Cr, As, Se) that are typically

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... ifficult to analyze with conventional quadrupole instruments. Sensitivities achieved with the DIHEN were higher (by factors ranging from 2 to 9) than those observed with a micronebulizer-spray chamber arrangement. Precision and detection limits were similar to or slightly improved over values obtained using the micronebulizer-spray chamber arrangement. The technique was successfully applied to the determination of Fe, Cr, Co, Cu, Pb, Al, Mn, Zn, Ag, and Sr on silicon wafer surfaces at a concentration range of (0.49-6.5) 6 10 9 atoms cm 22 , sampled by a 100 mL drop of H 2 O-H 2 O 2 -HF, as well as for the determination of Cr in DNA.