Empirical prediction of reduced ion mobilities of secondary alcohols

Abstract

Ion Mobility Spectrometry is a powerful method for the rapid identification of gas-phase analytes and finds its usage in various fields including the sensitive analysis of extremely complex and humid mixtures such as human breath when additional pre-separation techniques are applied. The output data from an ion mobility spectrometer (IMS), equipped with a Multi-Capillary Column (MCC) for pre-separation, is a chromatogram of the signal intensity versus a particular retention time and a specific reduced ion mobility which are the characteristics of the detected analyte. Hence, it is important to have a database of analytes with both the values for comparison and identification of peaks in any IMS chromatogram. Commonly, such databases are collected by measurements of reference analytes. It is obvious that a prognosis of the values, without the time consuming and costly reference measurements, would be a considerable facilitation for a preliminary identification of unknowns and development of databases. In this study, a correlation between the reduced ion mobilities and the number of carbon atoms was found for secondary alcohols. The correlation was then used to predict the reduced ion mobilities of other analytes in the same homologous series. To verify the accuracy of the prognosis, the analytes were measured individually using a 63 Ni-MCC-IMS and compared to the predicted values. The results of the prognosis show an accuracy higher than 99.5%.

How useful is molecular modelling in combination with ion mobility mass spectrometry for ‘small molecule’ ion mobility collision cross-sections?

“…There are a number of applications where prediction of CCS may be especially useful including: 1) generating libraries and thereafter utilising tCCSs as a confirmatory identification point for eCCSs 2) to confirm the identity of an analyte e.g. a drug metabolite 14 3) to predict ion mobility of analytes 15,16 and determine, in silico, the degree of separation in a mixture…”

“…(2) to confirm the identity of an analyte e.g. a drug metabolite 14 (3) to predict ion mobility of analytes 15,16 and determine, in silico, the degree of separation in a mixture…”

Characterization of Slow-Pyrolysis Bio-Oils by High-Resolution Mass Spectrometry and Ion Mobility Spectrometry

“…The highly linear mass-mobility correlations observed for these series (R 2 ≥ 0.995 for all CH 2 -homologous series represented in Figures 5−7), are consistent with structures having a common terminal group (or core unit) and a single, propagating alkyl chain. 37,38 The extent to which IM-MS is able to differentiate between possible isomers in a given homologous series is not fully understood. However, it is reasonable to expect that homologous series of isomers possessing different terminal groups would each follow a unique trendline.…”

Software tool for coupling chromatographic total ion current dependencies of GC/MSD and MCC/IMS

“…Wavelets became applied in a wide range [71][72][73][74][75][76][77][78][79], also pattern recognition procedures were developed [80]. Most recently, a procedure for automatic interpretation with respect to reference analytes used interpolation within the different members of classes of analytes was published [81,82].…”