Atmospheric Pressure Photoionization Mass Spectrometry: New Capabilities for the Determination of the Numbers of Components in Complex Mixtures and Their Identification

The atmospheric pressure photoionization and photochemical ionization mass spectrometry (APPI/APPCI−MS) makes it possible to compare the number of peaks in a mass spectrum with the number of components in the test mixture because of the measurements of the mass spectra of individual compounds, which mainly consist of the peaks of a molecular ion (M+) or a protonated molecule (MH+). The capabilities of gas chromatography–electron ionization (EI) and atmospheric pressure ionization mass spectrometry for the identification of trace components of complex mixtures are considered. The advantages of APPI/APPCI−MS, which makes it possible to increase the reliability of the detection of components in the complex mixtures of organic compounds, over EI mass spectrometry are shown. The work was performed at the Department of Analytical Chemistry, Faculty of Chemistry, Moscow State University.