Liquid chromatography-mass spectrometry of zwitterionic liquids | Cviterjonu šķidrumu hromatogrāfija-masspektrometrija
2010
Podjava, A., University of Latvia, Riga (Latvia) | Mekss, P., University of Latvia, Riga (Latvia) | Zicmanis, A., University of Latvia, Riga (Latvia)
The chromatographic results obtained in these studies show that acetonitrile-based mobile phases are superior in comparison with methanol mobile phases for the separation of basic impurities and ZILs. When operated in a gradient mode, these solvents allow shorter analysis time and improve peak shapes. HPLC in combination with tandem MS is capable to characterize all the impurities as well as to establish the fragmentation pattern of ZILs, which is quite similar. The main routes of fragmentation involve charge-induced dissociation at low CEs and homolytic cleavage of the alkyl chain at high CEs, respectively. Some unusual processes may proceed at high CEs, which possibly are based on gas phase carbocation chemistry and include several consecutive ring expansions promoted by the hydrogen transfer. However, the full fragmentation pathways can be proposed only after accurate mass measuring or isotopic labelling experiments.
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