Biological Sciences Division, Pacific Northwest National Laboratory, Richland, Washington 99352, United States.
Environmental and Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, Washington 99352, United States.
Anal Chem. 2020 Nov 17;92(22):14930-14938. doi: 10.1021/acs.analchem.0c02100. Epub 2020 Oct 26.
Ion packets introduced from gates, ion funnel traps, and other conventional ion injection mechanisms produce ion pulse widths typically around a few microseconds or less for ion mobility spectrometry (IMS)-based separations on the order of 100 milliseconds. When such ion injection techniques are coupled with ultralong path length traveling wave (TW)-based IMS separations (i.e., on the order of seconds) using structures for lossless ion manipulations (SLIMs), typically very low ion utilization efficiency is achieved for continuous ion sources [e.g., electrospray ionization (ESI)]. Even with the ability to trap and accumulate much larger populations of ions than being conventionally feasible over longer time periods in SLIM devices, the subsequent long separations lead to overall low ion utilization. Here, we report the use of a highly flexible SLIM arrangement, enabling concurrent ion accumulation and separation and achieving near-complete ion utilization with ESI. We characterize the ion accumulation process in SLIM, demonstrate >98% ion utilization, and show both increased signal intensities and measurement throughput. This approach is envisioned to have broad utility to applications, for example, involving the fast detection of trace chemical species.
从门、离子漏斗阱和其他常规离子注入机制引入的离子包，在基于离子迁移谱 (IMS) 的分离中产生的离子脉冲宽度通常约为几微秒或更短，而 IMS 分离的时间尺度约为 100 毫秒。当这种离子注入技术与使用用于无损离子操控的结构 (SLIMs) 的超长时间旅行波 (TW) 基 IMS 分离（即，秒级）结合使用时，对于连续离子源[例如电喷雾电离 (ESI)]，通常实现非常低的离子利用率。即使能够在 SLIM 装置中在更长的时间段内捕获和积累比传统方法可行的多得多的离子群体，随后的长分离也导致整体离子利用率低。在这里，我们报告了一种高度灵活的 SLIM 配置的使用，能够实现离子的同时积累和分离，并实现与 ESI 接近完全的离子利用率。我们在 SLIM 中对离子积累过程进行了表征，证明了 >98%的离子利用率，并显示了信号强度和测量通量的提高。这种方法预计在涉及痕量化学物质的快速检测等应用中具有广泛的用途。
