Gas Chromatography Mass Spectrometry (GC-MS) is a powerful analytical technique that combines two distinct methods, gas chromatography and mass spectrometry, to separate, identify, and quantify chemical compounds present in a sample.
Gas chromatography involves the separation of a mixture of compounds into individual components based on their different interactions with a stationary phase and a mobile gas phase. The mixture is injected into a heated column coated with a stationary phase, commonly composed of a polymer or silica material, which serves as a medium for the separation. As the mobile gas phase, typically an inert carrier gas such as helium, passes through the column, different compounds elute at different rates based on their interaction with the stationary phase.
Mass spectrometry, on the other hand, is a technique used to identify and determine the structure of individual compounds present in a sample. It involves the ionization of the separated compounds, their fragmentation, and the detection of the resulting ions based on their mass-to-charge ratio. The mass spectrometer measures the mass-to-charge ratio of the ions, providing information about the compound's molecular weight and pattern of fragmentation. This enables the identification of compounds based on their unique mass spectra, which can be compared to existing databases for identification purposes.
By coupling gas chromatography with mass spectrometry, GC-MS enables the separation and identification of complex mixtures with high sensitivity and selectivity. It is widely used in various fields such as environmental analysis, forensics, pharmaceuticals, and food analysis, as it allows for the identification and quantification of trace amounts of compounds present in a sample.
