Ion Mobility Spectrometry with High Ion Utilization Efficiency Using Traveling Wave-Based Structures for Lossless Ion Manipulations
Ailin Lia, Gabe Nagya, Christopher R. Conanta, Randolph V. Norheimb, Joon Yong Leea, Cameron Gibersona, Adam L. Hollerbacha, Venkateshkumar Prabhakaranc, Issac K. Attaha, Christopher D. Chouinarda, Aneesh Prabhakarana, Richard D. Smitha, Yehia M. Ibrahima, Sandilya V.B. Garimella
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 ultra-long path length traveling wave (TW)-based IMS separations (i.e., in the order of seconds), typically very low ion utilization efficiency is achieved for continuous ion sources. This paper explores how MOBILion's SLIM technology enables high ion utilization efficiency with a concurrent ion accumulation method.
The paper, published in Analytical Chemistry concludes:
- The potential of a highly flexible SLIM technology, enabling concurrent ion accumulation and separation and achieving near-complete ion utilization with ESI. The study shows characterization of ion accumulation process in SLIM, demonstrating >98% ion utilization, and both increased signal intensities and measurement throughput.
- The existing multiplexing strategies cannot be used because the multiple ion packets cycling in the system with multiple ion pulses being injected pose an as yet unsurmountable challenge as far as data deconvolution is concerned. A potential solution is to accumulate ions while a separation is ongoing (instead of discarding the ions) and use the accumulated ions for performing the subsequent run of the experiment along with highly efficient SLIM technology.
- This paper shows a new TW-SLIM module with decoupled accumulation and separation regions, which enables the IMS separation with multipass capabilities to be performed concurrently with ion accumulation over timescales of seconds. Thus, an overall high ion utilization efficiency is obtained.
- This SLIM technology coupled with a concurrent accumulation method is shown to achieve >90% overall ion utilization efficiency of ions introduced from a continuous source, like electrospray ionization (ESI) for instance, while maintaining SLIM ion manipulation capabilities.
- The signal intensities resulting from the ion populations with the concurrent accumulation approach in SLIM are shown to be as much as âˆ¼625-fold greater than using a conventional grid injection approach. This approach is envisioned to have broad utility to applications, for example, involving the fast detection of trace chemical species.
Analytical Chemistry 2020, 92, 22, 14930â€“14938 DOI: 10.1021/acs.analchem.0c02100