Capillary gas chromatography/mass
spectrometry analyses are carried out using a Thermoquest GCQ (ThermoFinnigan,
San Jose, CA) mass spectrometer system using electron impact (EI) and
chemical ionization (CI). Typical
electron energy is 70eV with the ion source temperature maintained at
200C. Isobutane is typically used as
the CI reagent gas. Individual components are separated using
capillary columns, like DB1 and DB5.
The injector temperature is typically set at 250C.The analysis of solids using a direct insertion probe are also carried out using the Thermoquest GCQ mass spectrometer.
This instrument is also capable of carrying out MS/MS experiments. Helium is used both as the collision gas and to improve trapping efficiency in the ion trap detector. The collision energy can be set between zero and the maximum available from the 10 volt tickle voltage.
