Effect of droplet lifetime on where ions are formed in electrospray ionization

Abstract

The location of gaseous ion formation in electrospray ionization under native mass spectrometry conditions was investigated using theta emitters with tip diameters between 317 nm and 4.4 μm to produce droplets with lifetimes between 1 and 50 μs.

A microdroplet-accelerated Biginelli reaction: mechanisms and separation of isomers using IMS-MS

“…Recently, the groups of Cooks, [17][18][19][20][21][22][23][24][25][26] Zare, [27][28][29][30][31][32][33][34][35][36][37][38][39] and others [40][41][42][43][44][45][46] have reported the acceleration of reactions in microdroplet environments during the process of electrospraying reagents into a mass spectrometer. 32 Intrigued by the possibility of faster rates for multicomponent reactions, we explored the use of microdroplets as a means of enabling a rapid Biginelli reaction (Scheme 2).…”

Hydrogen peroxide signaling via its transformation to a stereospecific alkyl hydroperoxide that escapes reductive inactivation

“…In native MS, ligand-protein complex ions are formed directly from aqueous buffered solutions at near neutral pH, which can result in the retention of non-covalent solution-phase interactions in the gas-phase on the timescale of ion desolvation and detection (<1 s). Thus, native MS can be used to measure ligand-protein dissociation constants reliably and in excellent agreement with alternative solution-phase biochemical assays [39][40][41][42] , particularly by using nanoscale ion emitter tips that reduce thermal destabilization of ligand-protein complexes during ion formation and transfer to the mass analyzer 39,43 . Importantly, native MS has shown to produce disassociation constants in excellent agreement with traditional spectroscopic methods 44 .…”

Reply to the ‘Comment on “The chemical reactions in electrosprays of water do not always correspond to those at the pristine air–water interface”’ by A. J. Colussi and S. Enami, Chem. Sci., 2019, 10, DOI: 10.1039/c9sc00991d

“…Whether those gas-phase clusters are produced inside the reaction chamber and/or if it happens inside the mass spectrometer might vary from one ESIMS to another. [2][3][4][5][6][7]23,[26][27][28][29] It is conceivable that during gas-liquid collision experiments, organic reactant(s) adsorb onto the water surface ( Fig. S4 in ref. 1), and even partially dissolve in the droplets, and during their passage for the mass spectrometric detection, chemical reactions take place in the gas-phase.…”