CEST has 4 GC stations to separate complex mixtures of volatile organic molecules in the gas phase. These GCs feature injection techniques such as split, splitless, and cool on-column and are equipped with the following detectors: flame ionization, electron capture, thermal conductivity and mass spectrometers. GC columns are available for a wide range of applications.
Flame Ionization Detector (FID): a good, general purpose detector for a wide variety of hydrocarbon compounds providing a wide linear dynamic range (ppm to ppb).
Electron Capture Detector (ECD): extremely sensitive for more electronegative molecules like halogenated compounds (pesticides for example).
Thermal Conductivity Detector (TCD): another general purpose detector but works best for the analysis of permanent gases (usually ppm detection limit).
Mass spectrometer detectors (MS): the Center has both quadrupole mass filter and quadrupole ion trap mass analyzers with electron ionization (EI) and chemical ionization (CI) sources. Both designs are very sensitive and in some cases can detect in the PPT range.
Quadrupole mass filters: rapid scanning (millisecond) analyzers with unit resolving power, nominal mass accuracy, and a mass range between 1 - 800 Daltons.
Quadrupole ion trap: rapid scanning (millisecond) analyzers with unit resolving power, nominal mass accuracy, and a mass range between 50 - 800 Daltons. Ions can be accumulated in the trap for improved mass spectral quality and for subsequent MS/MS experiments to help elucidate structure.
The Center’s GC assets are all able to use capillary columns. The HP 5890 GC is the only GC that can be fitted with packed columns.