Carbohydrate Structure Characterization by Tandem Ion Mobility Mass Spectrometry (IMMS)²

Abstract

A high resolution ion mobility spectrometer was interfaced to a Synapt G2 high definition mass spectrometer (HDMS) to produce IMMS-IMMS analysis. The hybrid instrument contained an electro-spray ionization source, two ion gates, an ambient pressure linear ion mobility drift tube, a quadrupole mass filter, a traveling wave ion mobility spectrometer (TWIMS) and a time of flight mass spectrometer. The dual gate drift tube ion mobility spectrometer (DTIMS) could be used to acquire traditional IMS spectra, but also could selectively transfer specific mobility selected precursor ions to the Synapt G2 HDMS for mass filtration (quadrupole). The mobility and mass selected ions could then be introduced into a collision cell for fragmentation followed by mobility separation of the fragment ions with the traveling wave ion mobility spectrometer. These mobility separated fragment ions are finally mass analyzed using a time-of-flight mass spectrometer. This results in an IMMS-IMMS analysis and provides a method to evaluate the isomeric heterogeneity of precursor ions by both DTIMS and TWIMS, to acquire a mobility-selected and mass-filtered fragmentation pattern and to additionally obtain traveling wave ion mobility spectra of the corresponding product ions. This new IMMS2 instrument enables the structural diversity of carbohydrates to be studied in greater detail. The physical separation of isomeric oligosaccharide mixtures was achieved by both DTIMS and TWIMS, with DTIMS demonstrating higher resolving power (70~80) than TWIMS (30~40). Mobility selected MS/MS spectra were obtained, and TWIMS evaluation of product ions showed that isomeric forms of fragment ions existed for identical m/z values.

Transversal Modulation Ion Mobility Spectrometry (IMS) Coupled with Mass Spectrometry (MS): Exploring the IMS-IMS-MS Possibilities of the Instrument

“…Hill et al 16 also illustrated the potential of the (IMS-MS) 2 approach in their study, where a drift tube ion mobility spectrometer (DTIMS) was coupled with a Synapt MS.…”

Mass spectrometry for glycosylation analysis of biopharmaceuticals

“…For example, in MS E -like approaches IM-separated precursor ions can be linked to their fragment ions via their drift time [47,72]. IM can also be applied to distinguish isomeric precursor structures via separation of their isomeric fragments [74].…”

Analyzing complex mixtures of drug-like molecules: Ion mobility as an adjunct to existing liquid chromatography-(tandem) mass spectrometry methods

“…Although its hyphenation with MS in commercial instrumentation is a more recent development, it has already created new possibilities for the characterization of some classes of small molecules and metabolites [9][10][11]. Specific examples are the separation of isomeric disaccharides [12][13][14] and metal(-ligand) complexes [15][16][17] or the characterization of carbohydrate, glycan and lipid structures [18][19][20][21][22][23]. Particular interest recently focused on the phenomenon of alternative charge sites in small molecules that are observed in the gas phase, i.e.…”