Simulation Study Of A New Linear Ion Trap With Octa-Electrodes

Linear ion trap is one hotspot in research of mass spectrometry at present, and a number of linear ion traps with novel structure have been developed so far. To improve the performance of linear ion traps and expand the application, a novel linear ion trap featuring octa. electrodes (OeLIT) was built, which was composed of eight identical columnar electrodes and two end electrodes. This work used the bevel shaped electrodes as an example to investigate mass analysis performance and realize ion directional ejection of OeLIT by applying specific unbalanced RF voltage. The relationship between RF voltage difference ratio (Delta) and internal electric field distribution was studied by software PAN33, and the mass spectra were achieved by AXSIM. It was turned out that the optimal mass resolution of OeLIT at m/z = 610 was 3660 when RF voltage difference ratio Delta was 40%. Compared with the performance of triangular. electrode linear ion trap (TeLIT), this result was improved up to 40%. The maximum efficiency of ion unidirectional ejection was up to 91% at Delta = 30%.