Characterization of the impact of the ejection slit on miniature rectilinear ion trap analysis

The rectilinear ion trap (RIT) has always been one of the ideal candidates for mass analyzer miniaturization because of its simple configuration. In this work, the effect of the ejection-slit dimensions on the ion ejection efficiency of a miniature rectilinear ion trap (mRIT) with full-scale dimensions of 5   mm   ×   4   mm   ×   25   mm was investigated by using SIMION8.1 simulation. Six mRITs with the same dimensions as those simulated and with different slit widths, whose X electrodes were fabricated by the stainless steel chemical etching process, were tested and characterized on a homemade mass spectrometer platform. It is shown that the ejection slit dimensions have a significant impact on both the signal intensity and mass resolution. For an mRIT with these full-scale dimensions, the optimized slit dimensions are 0.6   mm   ×   18   mm. The optimized mRIT demonstrated capabilities including a mass/charge range of over 1000   Th, unit mass resolution at m / z 332, and a passable tandem mass spectrometry capability, which are better than the non-optimized RIT with the same dimensions.