Gas chromatography is a method for separating the components of a solution and measuring their relative quantities. It is a useful technique for chemicals that do not decompose at high temperatures and when a very small quantity of sample (micrograms) is available. The use of gas chromatography is limited by the decomposition temperature of the components of the mixture and the composition of the column. Most columns cannot withstand temperatures greater than 250-350 °C.
In gas chromatography, a sample is rapidly heated and vaporized at the injection port. The sample is transported through the column by a mobile phase consisiting of an inert gas. Sample components are separated based on their boiling points and relative affinity for the stationary phase, which is most often a viscous liquid (wax) within the column. The higher a component's affinity for the stationary phase, the slower it comes off the column. The components are then detected and represented as peaks on a chromatogram.
