Combination of gas chromatography and chemical ionization mass spectrometry

Recent advances in the chemistry and biochemistry of cannabis

“…Recently helium has been employed as carrier-reactant gas. 61 The resulting spectra are very similar to standard El spectra. Using both techniques several aromatic phenols previously not detected in cannabis were identified: p-hydroxyacetophenone, catechol, o-and p-cresol, p-ethylphenol, phenol, p-vinylphenol, and tentatively, 4-hydroxy-3-methoxystyrene.…”

Mapping Glyceride Species in Biodiesel by High-Temperature Gas Chromatography Combined with Chemical Ionization Mass Spectrometry

“…Therefore, EI spectra alone are considered insufficient for unambiguous identification of compounds. 15 Unlike electron impact ionization, chemical ionization, in which ionized gases react with analyte molecules, often produces intact molecular ions and thus can provide complementary spectral information, 16,17 which is useful for enhancement of compound identification confidence. In addition to higher in-source collisional cooling owing to higher source pressure, preservation of molecular ions in chemical ionization is a function of the magnitude of exothermicity of ion formation reactions, which depend on the type of gas used in the ionization process.…”

Introduction to Gas Chromatography/High Resolution Mass Spectrometry

“…As with any successful technique, many improvements have been incorporated in recent years in order to provide the maximum amount of information that can be derived from a GC/MS analysis. Significant developments include the use of: a) glass capillary columns (1)(2)(3), for minimized surface effects and increased chromatographic resolution; b) direct interfacing of capillary columns to the mass spectrometer ion source (4)(5)(6)(7), to reduce sample losses in a molecular separator and to preserve chromatographic resolution by elimi nating large-volume connectors; c) high pressure ionization methods (e.g., chemical ionization, [8][9][10][11][12][13][14], to provide complementary in formation to assist in the interpretation of electron impact spectra; d) improved computer techniques, for automated data acquisition, data handling (15)(16)(17), spectrum recognition (18)(19)(20)(21)(22)(23) and interpretation (24)(25)(26).…”