Spesyvyi Anatolii, Španěl Patrik
J. Heyrovsky Institute of Physical Chemistry of Science, Academy of Science of the Czech Republic, Dolejškova 3, 18223, Prague 8, Czech Republic.
Department of Surface and Plasma Science, Faculty of Mathematics and Physics, Charles University in Prague, V Holešovičkách 2, 18000, Prague, Czech Republic.
Rapid Commun Mass Spectrom. 2015 Sep 15;29(17):1563-1570. doi: 10.1002/rcm.7254.
Selected ion flow tube mass spectrometry, SIFT-MS, used for trace gas analyses has certain fundamental limitations that could be alleviated by adding a facility that allows reaction times and ion interaction energies to be varied. Thus, a selected ion flow-drift tube, SIFDT, has been created to explore the influence of an embedded electric field on these parameters and on reaction processes.
The new SIFTD instrument was constructed using a miniature resistive glass drift tube. Arrival times of ions, t, analysed by a downstream quadrupole mass spectrometer over the m/z range 10-100 were studied by modulating the injected ion current using a gate lens. Single pulse modulation was compared with pseudorandom time multiplexing exploiting the Hadamard transformation. A simple model involving analysis of ethanol and water vapour mixture in air was used to explore the advantages of the SIFDT concept to SIFT-MS analysis.
It is shown that the resistive glass drift tube is suitable for SIFDT experiments. The Hadamard transformation can be used to routinely determine reagent ion residence time in the flow-drift tube and also to observe differences in arrival times for different product ions. Two-dimensional data combining arrival time and mass spectra can be obtained rapidly. The calculated ion drift velocities vary with the reduced field strength, E/N, and the calculated ion mobilities agree with theoretical and previous literature values.
This study has provided evidence that the SIFDT-MS technique can be implemented in a miniature and low-cost instrument and two- or three-dimensional data can be obtained (product ion count rates as functions of m/z, t and E/N) using the Hadamard transformation thus providing exciting possibilities for further analytical additions and extensions of the SIFT-MS technique. Copyright © 2015 John Wiley & Sons, Ltd.
用于痕量气体分析的选择离子流管质谱法（SIFT-MS）存在一些基本局限性，而增加一个能够改变反应时间和离子相互作用能的装置可以缓解这些局限性。因此，人们制造了一种选择离子流漂移管（SIFDT），以探究嵌入式电场对这些参数以及反应过程的影响。
新的SIFDT仪器采用微型电阻玻璃漂移管构建。通过使用栅透镜调制注入的离子电流，研究了下游四极杆质谱仪在m/z范围为10 - 100内分析的离子到达时间t。将单脉冲调制与利用哈达玛变换的伪随机时间复用进行了比较。使用一个涉及分析空气中乙醇和水蒸气混合物的简单模型，来探究SIFDT概念相对于SIFT-MS分析的优势。
结果表明，电阻玻璃漂移管适用于SIFDT实验。哈达玛变换可用于常规确定流动漂移管中试剂离子的停留时间，还可观察不同产物离子到达时间的差异。可以快速获得结合到达时间和质谱的二维数据。计算得到的离子漂移速度随折合场强E/N变化，计算得到的离子迁移率与理论值和先前文献值相符。
本研究提供了证据，表明SIFDT-MS技术可以在微型低成本仪器中实现，并且使用哈达玛变换可以获得二维或三维数据（产物离子计数率作为m/z、t和E/N的函数），从而为SIFT-MS技术的进一步分析扩展提供了令人兴奋的可能性。版权所有© 2015约翰威立父子有限公司。
