Implementation of orthogonal double resonance precursor and neutral loss scans on the Mini 12 miniature rectilinear ion trap mass spectrometer is described, and performance is compared to that of a commercial Thermo linear trap quadropole (LTQ) linear ion trap. The ac frequency scan version of the technique at constant rf voltage is used here because it is operationally much simpler to implement. Remarkably, the Mini 12 shows up to two orders of magnitude higher sensitivity compared to that of the LTQ. Resolution on the LTQ is better than unit at scan speeds of ~ 400 Th/s, whereas peak widths on the Mini 12, on average, range from 0.5 to 2.0 Th full width at half maximum and depend heavily on the precursor ion Mathieu q parameter as well as the pump down time that precedes the mass scan. Both sensitivity and resolution are maximized under higher pressure conditions (short pump down time) on the Mini 12. The effective mass range of the product ion ejection waveform was found to be 5.8 Th on the Mini 12 in the precursor ion scan mode vs. that of 3.9 Th on the LTQ. In the neutral loss scan mode, the product ion selectivity was between 8 and 11 Th on the Mini 12 and between 7 and 8 Th on the LTQ. The effects of nonlinear resonance lines on the Mini 12 were also explored.

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描述了在Mini 12微型直线离子阱质谱仪上实现正交双共振前驱物和中性损失扫描的性能，并与商用热线性阱四极杆（LTQ）线性离子阱的性能进行了比较。在此使用恒定射频电压下的交流频率扫描技术，因为它在操作上更容易实现。值得注意的是，与LTQ相比，Mini 12的灵敏度高出两个数量级。在约400 Th / s的扫描速度下，LTQ的分辨率优于单位，而Mini 12的峰宽平均范围为全宽度的0.5到2.0 Th（一半为最大值），并且在很大程度上取决于前体离子Mathieu q参数以及质量扫描之前的抽空时间。在Mini 12上较高的压力条件下（短的抽空时间），灵敏度和分辨率都得到了最大化。在前驱离子扫描模式下，Mini 12上产物离子喷射波形的有效质量范围为5.8 Th。 LTQ上的3.9 Th 在中性损失扫描模式下，Mini 12的产物离子选择性在8至11 Th之间，而LTQ在7至8 Th之间。还探讨了非线性共振线对Mini 12的影响。

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