Method and systems for analyzing ions using differential mobility spectrometry and ion guide comprising additional auxiliary electrodes

Abstract

Methods and systems for performing differential mobility spectrometry-mass spectrometry (DMS-MIS) are provided herein. In various aspects, methods and systems described may be effective to improve the performance of a differential mobility spectrometry device and a MS device operating in tandem relative to conventional systems for DMS-MS. In certain aspects, methods and systems in accordance with the present teachings utilize an ion guide which comprises a multipole rod set and a plurality of auxiliary electrodes to which a DC voltage is applied during transmission of ions through the ion guide so as to generate an axial electric field along a longitudinal axis of the ion guide to accelerate the ions toward the outlet end of the ion guide. This may significantly reduce a pause duration between the application of different compensation voltage values without substantially increasing the likelihood of contamination or cross-talk between groups of ions transmitted by the differential mobility spectrometry device at each compensation voltage value.