Detection mass bias in atmospheric pressure ionization mass spectrometry

Atmospheric pressure photoionization mass spectrometry.

Atmospheric pressure photoionization (APPI) is the last arrival in the family of atmospheric pressure ionization (API) methods to couple mass spectrometry (MS) to liquid-phase separation techniques. The basic idea was to further extend the fields of application of liquid chromatography (LC)-MS to those molecules that are not, or are poorly amenable, to electrospray (ESI) or APCI. The present re...

Development of atmospheric pressure ionization ion mobility spectrometry and ion mobility spectrometry mass spectrometry

Atmospheric pressure MALDI/ion trap mass spectrometry.

A new sample ionization technique, atmospheric pressure matrix-assisted laser desorption/ionization (AP MALDI), was coupled with a commercial ion trap mass spectrometer. This configuration enables the application-specific selection of external atmospheric ionization sources: the electrospray/APCI (commercially available) and AP MALDI (built in-house), which can be readily interchanged within mi...

"Magic" Ionization Mass Spectrometry

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...

Desorption Ionization Mass Spectrometry

Common to all experiments in mass spectrometry is the creation of gas-phase ions. Electron impact (EI) ionization is a familiar method for creating ions from volatile gas-phase molecules (M). In EI ionization, fast-moving electrons remove an electron from the neutral molecule to create the odd-electron molecular ion M`Õ. Another common ionization method is chemical ionization (CI). Here, an ion...