Fast screening of analytes for chemical reactions by reactive low‐temperature plasma ionization mass spectrometry

Abstract

LTP in this study serves both as an ambient ionization source for analyte identification (including reagents, intermediates and products) and as a means to produce reagent ions to assist gas-phase ion/molecule reactions. The present reactive LTP-MS method enables fast screening for several analytes from several chemical reactions, which possesses good reagent compatibility and the potential to perform high-throughput analyte screening. In addition, with the detection of various reactive intermediates (intermediates I and II of Eschweiler-Clarke methylation), the present method would also contribute to revealing and elucidating reaction mechanisms.

Analysis of ketone‐based neurosteroids by reactive low‐temperature plasma mass spectrometry

“…LTP has been widely applied to the analysis of petroleum, explosives, agrochemicals, fatty acid esters and drugs . In some cases, employing amine substances as reactants in LTP‐MS has helped to improve the ionization efficiency of analytes containing carbonyl groups . For example, methylamine, an accessible amine source, was used in our recent reactive LTP‐MS study of ketone‐based organic UV filters and showed the best performance characteristics of all tested amine and ammonium compounds …”

“…43 In some cases, employing amine substances as reactants in LTP-MS has helped to improve the ionization efficiency of analytes containing carbonyl groups. 44,45 For example, methylamine, an accessible amine source, was used in our recent reactive LTP-MS study of ketone-based organic UV filters and showed the best performance characteristics of all tested amine and ammonium compounds. 46 In this paper, a reactive LTP-MS method is introduced that allows for the detection of neurosteroids in brain tissue.…”

Intermediate detection in real time using reactive surface desorption dielectric‐barrier discharge ionization mass spectrometry

“…The signal at m/z 290, tentatively assigned as the protonated final imine, was clearly observed. The peak at m/z 273 was reported by the loss of NH 3 from the final imine . This may be due to the fragmentation of the final imine ( m/z 290) during ionization.…”

“…The Schiff‐base refers to the reaction between a class of compounds containing aldehydes (or ketones) and amino groups. The reaction generates a typical adduct intermediate which subsequently converts to an imine group (―C═N―) with the loss of 1 molecule of water …”

Easily fabricated ion source for characterizing mixtures of organic compounds by direct analysis in real time mass spectrometry

“…53 DART detection of organometallic compounds have involved some similar experiments by mixing the ligand and metal together prior to sampling, 77,78 and gas phase chemical reactions have been induced by low temperature plasma, 79,80 showing the potential for host-guest supramolecular chemistry with DART. Drawing from these experiments, we introduce the concept of using host-guest based supramolecular complexation chemistry directly in the gas phase, termed here reagent assisted desorption ionization (RADI), specically for the enhanced detection of neurotransmitters.…”