Ouyang Z, Badman ER, Cooks RG
Department of Chemistry, Purdue University, West Lafayette, IN 47907-1393, USA.
Rapid Commun Mass Spectrom. 1999;13(24):2444-9. doi: 10.1002/(SICI)1097-0231(19991230)13:24<2444::AID-RCM810>3.0.CO;2-F.
Two small (5 mm internal radius) cylindrical ion traps (CITs) are arranged in series and operated using a single ion source, detector and radio frequency (rf) trapping signal. Ions are trapped in the first CIT and later transferred to the second by applying a direct current (dc) pulse to the endcap electrode of the first trap. This process is facilitated if a second, appropriately timed, retarding dc pulse is applied to the exit endcap electrode of the second trap. Mesh endcaps are used for the CITs to increase the number of ionizing electrons entering the trap and to maximize the transfer efficiency and detected signal. The transfer efficiency is dependent on the amplitude of the dc potential applied to eject the ions from the first trap, the amplitude of the dc potential applied to retain the ions in the second trap, and the period during which the retarding potential is applied. The amplitude and phase of the rf also affect the transfer process. Ions that readily dissociate upon collision have low transfer efficiencies; more stable ions can be transferred with up to 50% efficiency. Copyright 1999 John Wiley & Sons, Ltd.
两个小型（内半径5毫米）圆柱形离子阱（CIT）串联排列，并使用单个离子源、探测器和射频（rf）捕获信号进行操作。离子被捕获在第一个CIT中，随后通过向第一个阱的端盖电极施加直流（dc）脉冲将其转移到第二个CIT中。如果向第二个阱的出口端盖电极施加第二个适时的减速直流脉冲，则有助于此过程。CIT使用网状端盖，以增加进入阱的电离电子数量，并使转移效率和检测信号最大化。转移效率取决于用于从第一个阱中喷射离子的直流电势的幅度、用于将离子保留在第二个阱中的直流电势的幅度以及施加减速电势的时间段。射频的幅度和相位也会影响转移过程。碰撞时容易解离的离子转移效率较低；更稳定的离子可以以高达50%的效率进行转移。版权所有1999约翰·威利父子有限公司。
