Department of Chemistry, Washington State University, Pullman, Washington 99164, United States.
Anal Chem. 2010 Nov 15;82(22):9336-43. doi: 10.1021/ac1017259. Epub 2010 Oct 22.
The design of a new ion mobility mass spectrometer (IM-MS) is presented. This new design features an ambient-pressure resistive glass ion mobility drift tube (RGIMS) coupled to a high-resolution time-of-flight mass spectrometer (TOFMS) by an enhanced interface that includes two segmented quadrupoles. The interface design demonstrates an increase in sensitivity while maintaining high resolving power typically achieved for ambient-pressure IMS drift tubes. Performance of the prototype instrument was evaluated and the analytical figures of merit for standard solutions as well as complex samples such as human blood were determined. For a 3 μM solution of caffeine, the peak was collected in 36 s and gave a response of 10 counts/s. The detection limit (defined as 1 count/s) was calculated to be 300 nM concentration of caffeine from the response rate from the 36 s run. Controlled fragmentation of caffeine was achieved through adjustment of voltages applied on the interface lenses. Over 300 tentative metabolites were detected in human blood along with 80 isomers/isobars with ion counts >5. Isotope ratios from extracted mass spectra of selected mobility peaks were used to identify selected metabolite compounds. High separation power for both IMS (resolving power, t(d)/Δt(w1/2), was 85) and MS (mass resolving power, m/Δm, maximum was 7000 with a mass accuracy between 2 and 10 ppm) was measured. Developed software for data acquisition, control and display allowed flexibility in instrument control, data evaluation and visualization.
介绍了一种新型离子淌度质谱仪（IM-MS）的设计。该新型设计采用常压电阻玻璃离子淌度漂移管（RGIMS），通过包括两个分段四极杆的增强接口与高分辨率飞行时间质谱仪（TOFMS）耦合。该接口设计在保持常压 IMS 漂移管通常达到的高分辨率能力的同时，提高了灵敏度。对原型仪器的性能进行了评估，并确定了标准溶液以及复杂样品（如人血）的分析性能。对于 3 μM 咖啡因溶液，在 36 s 内收集到峰，响应为 10 计数/s。通过从 36 s 运行的响应率计算，检测限（定义为 1 计数/s）被计算为 300 nM 浓度的咖啡因。通过调整接口透镜上的电压实现了咖啡因的受控碎裂。在人血中检测到超过 300 种疑似代谢物，以及离子计数>5 的 80 种异构体/同素异形体。从选定淌度峰的提取质谱中获得的同位素比用于鉴定选定的代谢物化合物。IMS（分辨率，t(d)/Δt(w1/2)，高达 85）和 MS（质量分辨率，m/Δm，最大为 7000，质量精度在 2 到 10 ppm 之间）都具有很高的分离能力。开发的数据采集、控制和显示软件允许仪器控制、数据评估和可视化具有灵活性。
