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 sk immer to suppress space charge effects in inductively coupled plasma mass s pectrometry (ICPMS). Electrons from this source can reduce the space charge repulsion between the positive ions in the ion beam. As a result, ion tran smission efficiency and analyte ion sensitivities are significantly improve d 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.