Plasma‐based ambient ionization mass spectrometry in bioanalytical sciences

Abstract

Plasma-based ambient ionization mass spectrometry techniques are gaining growing interest due to their specific features, such as the need for little or no sample preparation, its high analysis speed, and the ambient experimental conditions. Samples can be analyzed in gas, liquid, or solid forms. These techniques allow for a wide range of applications, like warfare agent detection, chemical reaction control, mass spectrometry imaging, polymer identification, and food safety monitoring, as well as applications in biomedical science, e.g., drug and pharmaceutical analysis, medical diagnostics, biochemical analysis, etc. Until now, the main drawback of plasma-based techniques is their quantitative aspect, but a lot of efforts have been done to improve this obstacle.

Investigation and Applications of In-Source Oxidation in Liquid Sampling-Atmospheric Pressure Afterglow Microplasma Ionization (LS-APAG) Source

“…ESI is widely used to ionize polar analytes in a broad mass range to provide MW information; thus when high DC voltage was applied to the syringe needle, and the polar analytes in the solution were ionized via ESI mechanism. In APAG mode, the analyte droplets formed at the capillary tip would produce gaseous molecules through thermal-assisted or gas-driven solvent evaporation, and then these gaseous molecules were ionized in the afterglow region via APAG mechanism similar to that occurring in the atmospheric pressure chemical ionization (APCI) source [13][14][15]. This APAG mode is more suitable for thermostable, weakly polar or nonpolar small molecules.…”

“…In recent years, numerous plasma-based ionization techniques under atmospheric pressure or ambient conditions [13][14][15][16][17] are emerging as powerful tools for rapid analysis of diverse analytes, which can also employ Breactive^plasma as the ionization reagent to initiate various types of reactions [18][19][20][21], including conventional chemical reactions, electrochemical or photochemical reactions, and gas-phase ion-molecule reactions. In-source oxidation, as a common reaction in the ionization process, should be avoided in routine analysis but has been successfully applied in structural analysis [7].…”

A Radical-Mediated Pathway for the Formation of [M + H]+ in Dielectric Barrier Discharge Ionization

“…This is of fundamental interest in plasma-based and related atmospheric pressure ionization methods, since protonated molecules ([M + H] + ) are predominantly observed in positive ion mode [1]. It is commonly believed that the protons originate from hydronium and/or solvent clusters [1][2][3][4][5], according to Kebarle's water displacement reaction (Equation 1) [6]:…”

The 2017 Plasma Roadmap: Low temperature plasma science and technology

“…The SCGD and LS-APGD devices mentioned above are examples used for direct analysis of sample solutions, but they can also be employed with gaseous samples, using either optical or MS detection, and in the open atmos phere. A special class of atmospheric-pressure plasmas are now lumped into the general category of sources for ambient desorption/ionization and coupled with MS [149]; an example is the flowing atmospheric-pressure afterglow (FAPA) shown in figure 29 (right). These ambient MS sources include not only GDs but also coronas, dielectric-barrier discharges (DBDs) and microwave-sustained sources.…”