Department of Chemistry, Washington State University, Pullman, Washington 99164, USA.
Anal Chem. 2011 Feb 15;83(4):1260-7. doi: 10.1021/ac1021002. Epub 2011 Jan 21.
Ion mobility spectrometry (IMS) is a rapid, gas-phase separation technique that exhibits excellent separation of ions as a standalone instrument. However, IMS cannot achieve optimal separation power with both small and large ions simultaneously. Similar to the general elution problem in chromatography, fast ions are well resolved using a low electric field (50-150 V/cm), whereas slow drifting molecules are best separated using a higher electric field (250-500 V/cm). While using a low electric field, IMS systems tend to suffer from low ion transmission and low signal-to-noise ratios. Through the use a novel voltage algorithm, some of these effects can be alleviated. The electric field was swept from low to high while monitoring a specific drift time, and the resulting data were processed to create a 'voltage-sweep' spectrum. If an optimal drift time is calculated for each voltage and scanned simultaneously, a spectrum may be obtained with optimal separation throughout the mobility range. This increased the resolving power up to the theoretical maximum for every peak in the spectrum and extended the peak capacity of the IMS system, while maintaining accurate drift time measurements. These advantages may be extended to any IMS, requiring only a change in software.
离子迁移谱（IMS）是一种快速的气相分离技术，作为一种独立的仪器，具有出色的离子分离能力。然而，IMS 不能同时实现对小离子和大离子的最佳分离效果。类似于色谱中的一般洗脱问题，使用低电场（50-150 V/cm）可以很好地分离快速离子，而使用较高的电场（250-500 V/cm）则可以更好地分离缓慢漂移的分子。在使用低电场时，IMS 系统往往会受到低离子传输和低信噪比的影响。通过使用新颖的电压算法，可以缓解其中的一些影响。电场从低到高扫描，同时监测特定的漂移时间，处理得到的数据以创建“电压扫描”光谱。如果为每个电压计算最佳的漂移时间并同时扫描，那么可以获得整个迁移率范围内具有最佳分离效果的光谱。这提高了每个光谱峰的分辨率，达到了理论最大值，并扩展了 IMS 系统的峰容量，同时保持了准确的漂移时间测量。这些优势可以扩展到任何 IMS，只需要更改软件即可。
