Dopant-assisted direct analysis in real time mass spectrometry

摘要

The present invention is directed to a method of Direct Analysis in Real Time (DART) analysis with a carrier gas in the addition of an efficient dopant to the carrier gas stream exiting the DART source. Charge-exchange and proton transfer reactions are observed with the addition of dopants such as toluene, anisole, and acetone. The argon DART mass spectrum in the presence of an efficient dopant was dominated by molecular ions for aromatic compounds, whereas the helium DART mass spectrum of the same aromatic showed both molecular ions and protonated molecule species. Fragment ions generated from analysis with argon gas in the presence of an efficient dopant can be used to distinguish isobaric analytes.