Gas Chromatography (GC): An Overview
Gas chromatography, often abbreviated to GC, is one of the most powerful techniques in the analytical chemist’s toolset. It employs a range of components to separate gas-phase compounds and measure them based on their constituent parts. This is a high-sensitivity technique that can enable analyses of gases at concentrations of just a few parts per million (ppm), with a wide range of application areas.
What is Gas Chromatography & How Does it Work?
Gas chromatography separates, identifies, and measures the different compositional elements in a given sample by vaporizing it and measuring the time taken for different components to elute from the system. Once the sample is converted to a mobile phase, it is passed through a stationary medium by an inert carrier gas. Sample molecules within the mobile phase react differently with the stationary medium, causing them to elute at different rates.
A detector monitors the eluent and identifies each component as a function of time, typically expressed as a series of peaks on a chart. The finished chart will comprise a series of peaks corresponding to all the components within the compound; what is known as a gas chromatograph.
The Components of Gas Chromatography
Though all types of gas chromatography conform to these basic principles, there are myriad types of them available to chemists today. Consequently, there are numerous components that may be used in a typical gas chromatograph. These include, but are by no means limited to:
- Sample injector, to introduce small quantities of sample material into the system.
- Vaporizer, to heat the sample to the point of evaporation.
- GC column, which is packed with a stationary phase porous medium.
- A detector, such as an electronic detector or a mass spectrometer (MS).
- Software, to process electronic/spectral peaks into a gas chromatograph.
Gas chromatography is an extremely flexible technique that encompasses a wide range of different systems. As a result, the potential fields of application are extremely varied. These can largely be broken down into one of two groups: analytical or preparative GC.
Analytical gas chromatography can be used to quantify a wide range of substances in a variety of sample types – provided they are not prone to decomposition. Quantification of volatile organic compounds (VOCs), toxic industrial chemicals (TICs), chemical warfare agents (CWAs), and much more is possible with high-performance analytical gas chromatography. Preparative GC, meanwhile, is ideal for purifying specific analytes for further application downstream.
Gas Chromatography with Lambda
At Lambda Advanced Technology, we supply high-quality instruments manufactured by industry-leaders in analytical equipment manufacturing. Among these is a suite of gas chromatography systems with built-in detectors for ease-of-use and accurate performance, whether in the lab or in the field. If you would like to learn more, simply contact a member of the team today.