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

•The first CCS database for the main EAs has been created and cross-validated.•Epimers can be distinguished in the TWIMS dimension (∆CCS ∼ 3-4%).•The integration of TWIMS in the LC-MS workflow improves the S/N between 2.5 and 4 times.•EAs are separated from matrix interferences that co-elute in LC and have the same m/z.•The method has been characterized for the determination of 12 EAs in cereal samples. This work evaluates the potential of ion mobility spectrometry (IMS) to improve the analytical performance of current liquid chromatography-mass spectrometry (LC-MS) workflows applied to the determination 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 models. 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 resolution 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 improved 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.