Structural characterization of ions using differential mobility spectrometry (DMS) and spectroscopy - implications for modeling the DMS process

点击翻译按钮获取中文摘要

Differential Mobility Spectrometry, or DMS, is emerging as a power tool for use in a rapidly growing numberand variety of applications involving ion detection and characterization. Analytical laboratories associated withthe pharmaceutical industry, medical research, and environmental monitoring are all now employing DMStechnology. DMS characterizes charged chemical species by their mobility through an inert gas under dynamicelectric field conditions. Ions are separated based on their mass-to-charge ratios, their shapes, and how theyinteract with the gas in the collision cell. Instrument sensitivities are typically on the parts-per-billion toparts-per-trillion range. Recently, in collaboration with researchers at SCIEX, we demonstrated that dynamicclustering and de-clustering lies at the origin or the enhanced separation displayed by DMS in comparison withother separation techniques. Moreover, we have demonstrated that instrument conditions can be tuned such thatthe species being probed will exhibit either gas-phase or solution-phase properties, and that the clusteringpropensities of ions correlate strongly with their condensed phase properties. This work, which is conducted inpartnership with SCIEX, will provide an unambiguous structural characterization of the molecular ions whichare separated and isolated by DMS.Here, we will characterize the DMS behaviour of a variety of compounds while simultaneously probing thesespecies with high-resolution laser spectroscopy. These studies will also be supported by high-level quantumchemical calculations. The experimental and computational results that we obtain will be used to build adatabase to which we will apply machine learning. This work will provide a deep, fundamental description ofthe dynamic clustering environment in the DMS instrument, and will provide an unambiguous picture of therelationship between an ion's structure and its physicochemical properties in the gas- and condense-phases.This information is critical for the development for DMS-based physicochemical properties assays.