Physicochemical Property Correlations with Ionization Efficiency in Capillary Vibrating Sharp-Edge Spray Ionization (cVSSI).

The relative contributions to ionization efficiency by three molecular chemical properties have been examined for field-free and field-enabled capillary vibrating sharp-edge spray ionization (cVSSI) using mass spectrometry (MS) analysis. Ion intensities have been recorded for model compounds under each operational ionization mode as well as for aqueous and nonaqueous (methanol) solvent systems. Multiple regression analysis suggests that for field-free cVSSI, ion intensity is mostly associated with the log of the base dissociation constant (p) and proton affinity (PA) for both aqueous and methanol solutions.

Rapid Solution-Phase Hydrogen/Deuterium Exchange for Metabolite Compound Identification.

Rapid, solution-phase hydrogen/deuterium exchange (HDX) coupled with mass spectrometry (MS) is demonstrated as a means for distinguishing small-molecule metabolites. HDX is achieved using capillary vibrating sharp-edge spray ionization (cVSSI) to allow sufficient time for reagent mixing and exchange in micrometer-sized droplets. Different compounds are observed to incorporate deuterium with varying efficiencies resulting in unique isotopic patterns as revealed in the MS spectra.