Reduction of space charge effects in inductively coupled plasma mass spectrometry using a supplemental electron source inside the skimmer: ion transmission and mass spectral characteristics

An electron source consisting of a heated filament has been added to the skimmer to suppress space charge effects in inductively coupled plasma mass spectrometry (ICPMS). Electrons from this source can reduce the space charge repulsion between the positive ions in the ion beam. As a result, ion transmission efficiency and analyte ion sensitivities are significantly improved across the full mass range. MO+/M+ abundance ratios are not affected, M2+/M+ abundance ratios increase only slightly, and no new background ions are created by this electron injection technique.