The measurement of deprotonation sites in multifunctional molecules following electrospray ionization is important to better inform a wide range spectroscopic and photophysical studies that use prepare molecular species for study the gas phase. We demonstrate low-resolution UV–vis laser photodissociation spectroscopy can be applied situ identify deprotomers three coumaric acids, trans-para-coum...

A novel, simple, and sensitive method for the determination of jujuboside A in rat plasma using liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) was developed. Following solid-phase extraction, measurement of jujuboside A was performed by negative ion electrospray ionization (ESI) in multiple reaction monitoring (MRM) mode. The limit of detection was 1.25 ng/mL, and the lowe...

The systematic study of the temperature and pressure dependence of matrix-assisted ionization (MAI) led us to the discovery of the seemingly impossible, initially explained by some reviewers as either sleight of hand or the misinterpretation by an overzealous young scientist of results reported many years before and having little utility. The “magic” that we were attempting to report was that w...

The effect of solvent conditions, including pH, on product ion spectra obtained from precursor ions produced by electrospray ionization (ESI) was examined. Bovine carbonic anhydrase 2 was used as a model protein and the product ions generated by collision induced dissociation of the whole protein were measured under several different solvent conditions (pH 5.0, 3.7, and 0.1% HCOOH (pH 2.6)/MeCN...

We present a software tool for visualizing data obtained from analyzing complex peptide mixtures by liquid chromatography (LC) electrospray ionization (ESI) mass spectrometry (MS). The data are represented as a two-dimensional density plot. For experiments employing collision-induced dissociation (CID), links are embedded in the image to the CID spectra and the corresponding peptide sequences t...

Native electrospray ionization-mass spectrometry, with gas-phase activation and solution compositions that partially release subcomplexes, can elucidate topologies of macromolecular assemblies. That so much complexity can be preserved in gas-phase assemblies is remarkable, although a long-standing conundrum has been the differences between their gas- and solution-phase decompositions. Collision...