Gas Chromatography/Mass Spectrometry (GC/MS)

Gas Chromatography/Mass Spectrometry (GC/MS) can be used for a wide variety of applications at McCrone Associates. These applications include chemical contaminant analysis, residual solvent analysis, odor analysis, drug identification, and explosives analysis among others. 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 a Thermo Scientific 1310 gas chromatograph with ISQ LT mass spectrometer.

The Thermo 1310 with ISQ MS is a modular system and is capable of multiple configurations to best suit specific analytical needs. The system includes: split / splitless inlet, programmable temperature vaporizing inlet liquid sample introduction headspace sample introduction, and solid phase microextraction (SPME) sample introduction.

The system is equipped with multiple detectors as well and can be operated with: single quadrupole electron impact ionization (EI) mass spectrometer, chemical ionization (CI) mass spectrometer, flame ionization detector (FID), nitrogen / phosphorous detector (FPD).

NIST and Wiley commercial libraries are available for spectral comparisons.