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Gas chromatography (GC) is a separation technique based on the repeated partition or adsorption, between a mobile phase and a stationary phase, of components to be separated. The mobile phase is always a gas known as the carrier gas. The stationary phase can be either a solid or a liquid.
Traditionally, the scope of gas chromatography has been for the separation of the following:
- Complex mixtures
- Components closely related chemically and physically
- Mixtures consisting of a wide breadth of compounds
Mass spectrometry is the analytical technique that provides the most structural information for the least amount of analyte material. It provides qualitative and quantitative information about the atomic and molecular composition of inorganic and organic materials and their chemical structures. As an analytical technique it possesses distinct advantages:
- Increased sensitivity over most other analytical techniques because the analyzer, as a mass-charge filter, reduces background interference.
- Excellent specificity from characteristic fragmentation patterns to identify unknowns or confirm the presence of suspected compounds. closely related chemically and physically
- Information about molecular weight
- Information about the isotopic abundance of elements
The combined analytical technique GC-MS became - since the eighties - the most powerful method for the analysis of organic compounds such as drugs, pesticides, pollutants and their metabolites in clinical, forensic and food chemical determinations. It is also used in doping control as well as in environmental and occupational toxicology.
References
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D. Harvey, “Modern Analytical Chemistry”, McGraw-Hill Companies Inc., (2000)
- K. Pfleger et al. “Mass Spectral and GC Data of Drugs, Poisons, Pesticides, Pollutants and their Metabolites”, 2nd Edition, VCH, 1992E. C. McGoran, J. Chem. Educ., 68, 19-23 (1991)
- H.M. McNair, J.M. Miller, “Basic Gas Chromatography”, John Wiley &Sons, (1997)
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