Multivariate mixture analysis using reduced-mass-resolution membrane introduction mass spectrometry and variable selection

摘要

Abstract: The feasibility of analyzing mixtures of spectrally similar analytes with low resolution mass spectrometers coupled with membrane introduction was studied. The performance of the multivariate calibration of an isometric ethyl benzene and p-xylene mixture remained essentially unchanged as the mass resolution degraded. The calibration performance also improved slightly as the data used for calibration decreased from the full mass spectra to only 12 or 18 fragment ions judiciously chosen by variable selection. The multivariate calibration and prediction for a more complex mixture of benzene and toluene only degraded slightly as the resolution decreased, while the result for the two isomers ethyl benzene and p-xylene got progressively worse. Depending on the variable selection algorithm and the number of fragment ions used, using only a select few ions for multivariate calibration and prediction gave results that were either similar to or slightly worse than results using the entire mass spectra. This paper demonstrates that mixture analysis performed with membrane introduction coupled to future miniature, low resolution mass spectrometers is possible. !27