Ion mobility-mass spectrometry to extend analytical performance in the determination of ergot alkaloids in cereal samples

Abstract

This work evaluates the potential of ion mobility spectrometry (IMS) to improve the analytical perfor- mance of current liquid chromatography-mass spectrometry (LC-MS) workflows applied to the determi- nation of ergot alkaloids (EAs) in cereal samples. Collision cross section (CCS) values for EA epimers are reported for the first time to contribute to their unambiguous identification. Additionally, CCS values have been inter-laboratory cross-validated and compared with CCS values predicted by machine-learning mod- els. Slight differences were observed in terms of CCS values for ergotamine, ergosine and ergocristine and their corresponding epimers (from 3.3 to 4%), being sufficient to achieve a satisfactory peak-to-peak res- olution for their unequivocal identification. A LC-travelling wave ion mobility (TWIM)-MS method has been developed for the analysis of EAs in barley and wheat samples. Signal-to-noise ratio (S/N) was im- proved between 2.5 and 4-fold compared to the analog LC-TOF-MS method. The quality of the extracted ion chromatograms was also improved by using IMS.