TECHNICAL FIELD

Embodiments herein generally relate to processing analytical data and, more specifically, to predicting collision cross-section values based on analytical information derived from ion mobility analysis of a sample.

BACKGROUND

Ion mobility spectrometry or separation (IMS) is a widely used technique for identifying and quantifying compounds within a sample. In general, IMS operates by separating gas-phase ions based on their shape, size, and charge by subjecting the ions to a weak electric field in the presence of an inert buffer gas, such as nitrogen or helium. Ions of different sizes and shapes will have different collision frequencies with the inert buffer gas as the ions flow through a separation or mobility cell of an IMS device. Collisions between the ions and the inert buffer gas under the influence of the electric field produce differences in drift time of ions (i.e., ions with a higher collision frequency will have a higher drift time compared with ions with a lower collision frequency). Properties associated with IMS include the drift time, ion mobility, collision cross-section (CCS) or (Ω), and/or reduced CCS (Ω′). Ions separated by IMS may be introduced into a mass analyzer (e.g., a mass spectrometer (MS)) to determine further physiochemical properties, such as mass-to-charge (m/z) ratios.

The use of CCS for identification and confirmation of compound identity in sample experiments may provide orthogonal compound characteristics, under given experimental conditions, to retention time and tandem MS information. However, conventional approaches are deficient for widespread use due to, among other things, a lack of CCS measurements in compound libraries and the availability of computational tools to rapidly generate theoretical CCS values. Accordingly, analysts using CCS to evaluate sample components may benefit from methods of obtaining CCS values that are more efficient and effective than conventional systems.

