Gas Chromatography for Beginners | Chromatography Excellence

A small aliquot of the sample is introduced into the gas chromatography (GC) system, typically as a liquid or gas phase. The sample is vaporized within the injector port, where it is subjected to heating to ensure complete volatilization if not already in the gaseous state. An inert carrier gas, such as helium, nitrogen, or hydrogen, facilitates the transport of the vaporized sample through the chromatographic column. The core component of the GC system is the separation column, which contains a stationary phase that may be either a liquid or solid phase coated onto a support material. The choice of stationary phase is contingent upon the chemical properties of the analytes under investigation. As the sample traverses the column, its components are separated based on differential interactions with the stationary phase. Compounds with lower boiling points or weaker interactions typically elute first, followed by those with higher boiling points or stronger interactions. Upon exiting the column, the separated components are detected by a detector that converts their presence into an electrical signal. These signals are subsequently recorded and represented as a chromatogram, a graphical depiction of detector response as a function of time. Each peak in the chromatogram corresponds to an individual component within the sample. The retention time and peak area are used to identify and quantify the components.