Effect of Amplitude-Scanning ac on the Performance of Ion Trap Mass Spectrometry

With the wide application of ion trap mass spectrometry, the theoretical simulation and experimental verification of resonant ejection play an important role in improving the performance of ion trap mass spectrometry. There are two common ways to set the (alternating current) (ac) resonant voltage of ion trap, one is to set a small constant value like 1 V_0-p, and the other is to set an amplitude-scanning range. However, few people has studied the influence of the amplitude-scanning setting of ac on the analytical performance of ion trap mass spectrometry, and no experimental result has been studied by theoretical simulation neither. In this work, based on a homemade miniaturized ion trap mass spectrometry platform with continuous atmospheric pressure interface, the effect of amplitude-scanning resonance on the performance of ion trap mass spectrometry was studied by theoretical simulation and experimental study using a nano electrospray ionization source, and reserpine was used as the research object. Firstly, the effects of constant ac resonant ejection and amplitude-scanning ac resonant ejection on the resolution and sensitivity of ion trap mass spectrometry were studied experimentally. The experimental results showed that amplitude-scanning resonant ac ejection could improve the resolution and sensitivity of ion trap mass spectrometry, SIMION showed that the amplitude-scanning ac resonant ejection could prevent the ions from being excited in advance compared with the constant ac resonant ejection subsequently. Finally, the application experiments of two kinds of ions, fentanyl and narcotine showed that the resolution of amplitude-scanning ac resonant ejection was more than 2 times higher than that of constant ac resonant ejection. In conclusion, the effect of amplitude-scanning ac on the performance of ion trap mass spectrometry was studied by theoretical simulation and experimental comparison, and the theoretical simulation method and related program of resonance excitation process of ion trap mass spectrometry were established, which laid a foundation for further study of more complex nonlinear resonance and other high-order motion in ion trap. At the same time, the conclusions also help to improve the analytical performance of ion trap mass spectrometry to a certain extent, and accelerate the instrument debugging process of ion trap mass spectrometry.