Exploring the Complexity of Steviol Glycosides Analysis Using Ion Mobility Mass Spectrometry.

Abstract

A proof of principle method using ion mobility-mass spectrometry (IM-MS) and collision induced dissociation (CID) coupled with micro flow ultra high-performance chromatography (UHPLC-IM-MS) has been developed to screen for steviol glycosides. Traveling wave ion mobility was used to determine rotationally averaged collision cross sections in nitrogen buffer gas (TWCCSN2). To explore the evolving applicability of ion mobility screening, the analytical approach was initially developed and applied to the analysis of a steviol/steviol glycoside spiked chocolate spread extract. Subsequently 55 food commodities were screened using a steviol glycoside TWCCSN2 library. IM analyses produced TWCCSN2 values, enabling the unequivocal identification of the steviol glycosides and isomeric pairs (negating the reliance on product ions). In addition, coeluting isomeric species, comprising (labile fragment ions, doubly charged dimers, and multiply charged species) have been identified and resolved. Isomeric false detections were avoided, with the coeluting isomeric species quantified. A quantitative assessment of TWCCSN2 in the analysis of steviol glycosides was performed.