Theoretical Research on Performance Optimization of PCB Voltage-Divided Ion Trap Mass Analyzer

Printed-circuit-board voltage-divided ion trap （PCBVDIT） is a novel mass analyzer with simple electrode structure, mainly composed of printed circuit boards. PCBVDIT is a good choice for the analyzer of miniaturized ion trap mass spectrometer for the reason that PCBVDIT has a compact size, easy process and assembly technology and low cost. The operation mode and geometry structure of a prototype PCBVDIT were improved in order to enhance its analytical performance. The internal electric field distribution of PCBVDIT was calculated by PAN_33. Ion trajectories inside the PCBVDIT and simulated mass spectrum peaks for different electrode structures besides different operation modes were both simulated by software SIMION and AXSIM. The ions used in the simulation experiments were m/z 4 000, 4 001 and 4 002. It shows that different voltage-divided ratios of supplement resonance signal has a significant influence on the resolving power of PCBVDIT, even though the voltage-divided ratio of radio frequency trapping waveform remains unchanged. With the reduction of voltage-divided ratio of supplement resonance signal, mass resolution could be improved. In the limit case, mass resolution would be improved by about 25% when the supplement resonance signal was only applied to the central electrode, that is, the voltage-divided ratio of supplement resonance signal was equal to zero. On the other hand, enhanced performance, with a mass resolution up to 10 325 for the ions which had the mass-to-charge ratio of 4 001, could be acquired on the structure-optimized PCBVDIT by removing the corner electrodes from the prototype. These simulated results could provide a theoretical foundation for further investigations.