Dual Capillary-based Vibrating Sharp-edge Spray Ionization (cVSSI) with On-line Solution-phase Hydrogen/Deuterium Exchange for Distinguishing Carbohydrates Isomers

In-droplet hydrogen-deuterium exchange (HDX) combined with mass spectrometry (MS) has been used to characterize the reactivities of monosaccharide (3 pairs), disaccharide (4 pairs), and glycan (1 pair) isomer compounds. To accomplish in-droplet HDX, capillary vibrating sharp-edge spray ionization (cVSSI) employing a dual emitter tip setup is utilized. The solution-phase HDX technique is shown to be extremely reproducible for these measurements such that several different isomer sets can be distinguished by their unique isotopic distributions in the mass spectrum. The results are discussed in light of their applicability toward identifying metabolite compounds in complex metabolomics mixtures.