Gas Chromatography/Mass Spectrometry (GC/MS) can be used for a wide variety of applications at McCrone Associates. These applications include residual solvent analysis, odor analysis, drug identification, explosives and fire debris. GC/MS is one of the most prominent techniques currently used in analytical laboratories for the identification of volatile and semi-volatile compounds. Because it is a separation technique, it is very useful for samples that are mixtures.

GC/MS is most commonly used in the electron ionization (EI) mode. The GC is used to separate components of a sample, and then the mass spectrometer ionizes each compound and scans the mass of the fragments generated. The scan of the fragments results in a pattern that is called the mass spectrum for that compound. The mass spectrum is unique for many compounds and is used to help determine the identity of a material or one or more components of a compound. The mass spectrum can be compared to reference libraries of known compounds in order to be identified.

Instrumentation:

McCrone Associates uses two Agilent 6890 Gas Chromatographs:

One configured with an Agilent 5973N EI and CI, upgraded Mass Selective Detector (GCMS), a flame ionization detector (FID), electronic pneumatic gas flow controllers and library searching capabilities against the Wiley Version 8 library with NIST entries.

One configured with an Agilent 5975 EI and CI Mass Selective Detector (GCMS), an Antek 7090 nitrogen-specific Thermal Energy Analysis Detector (GCTEA), electronic pneumatic gas flow controllers and library searching capabilities against the Wiley Version 8 library with NIST entries.