Xu Hualei, Zhang Xiaohua, Wang Yuzhuo, Ling Xing, Tian Di
College of Instrumentation and Electrical Engineering, Jilin University, Changchun, 130012, China.
Department of Chemistry, Fudan University, Shanghai, 200433, China.
Rapid Commun Mass Spectrom. 2016 Apr 30;30(8):1079-86. doi: 10.1002/rcm.7517.
The ion funnel has proven to be an important ion transport device. It is used in mass spectrometry as a replacement for the ion transmission limited skimmer. However, conventional out-of-phase radiofrequency (RF) supply approaches inevitably produce potential barriers, decreasing transmission efficiency. A novel RF supply method is proposed that produces better transmission performance.
We designed an ion funnel driven by a phase-modulated rectangular wave (PMRW). The potential field distributions of the PMRW ion funnel and a conventional ion funnel were computer simulated to evaluate their focusing properties. A series of simulations were produced using the SIMION ion-optics simulation program to compare the transmission efficiency of the two types of funnel. Preliminary experimental results were obtained using an electrospray ionization mass spectrometry platform with polypropylene glycol, propylamine and butylamine samples.
The electrical potential distribution of a PMRW ion funnel has a bowl shape at the cross section of the electrodes, rather than in the field-free region; this benefits focusing performance. A comparison of ion trajectories and flight time data produced by the SIMION simulations showed that the potential barrier did not exist in the PMRW mode. The experimental results showed that the PMRW method increased the signal intensity by 150-200% for propylamine and butylamine and 50% for polypropylene glycol.
A novel PMRW ion funnel has been designed and developed. The simulation and experimental results indicate that the PMRW ion funnel has better transmission efficiency than the conventional ion funnel, particularly for low mass-to-charge ratio ions.
离子漏斗已被证明是一种重要的离子传输装置。它在质谱分析中被用作离子传输受限的分离器的替代品。然而，传统的异相射频（RF）供应方法不可避免地会产生势垒，从而降低传输效率。本文提出了一种能产生更好传输性能的新型RF供应方法。
我们设计了一种由相位调制矩形波（PMRW）驱动的离子漏斗。通过计算机模拟PMRW离子漏斗和传统离子漏斗的势场分布，以评估它们的聚焦特性。使用SIMION离子光学模拟程序进行了一系列模拟，以比较两种漏斗的传输效率。利用配备聚丙二醇、丙胺和丁胺样品的电喷雾电离质谱平台获得了初步实验结果。
PMRW离子漏斗在电极横截面处的电势分布呈碗状，而非在无场区；这有利于聚焦性能。通过SIMION模拟产生的离子轨迹和飞行时间数据的比较表明，PMRW模式下不存在势垒。实验结果表明，PMRW方法使丙胺和丁胺的信号强度提高了150 - 200%，使聚丙二醇的信号强度提高了50%。
设计并开发了一种新型的PMRW离子漏斗。模拟和实验结果表明，PMRW离子漏斗比传统离子漏斗具有更好的传输效率，特别是对于低质荷比离子。
