Gas chromatography is an instrumental technique for separating components of a mixture based on their boiling point, polarity, and affinity to a gas chromatography column. Since samples must be vaporized prior to analysis by GC, this technique is commonly used for analysis of volatile and semi-volatile organic compounds such as solvents, fuels, most CWAs, pharmaceutical and illicit drugs, and other chemicals that are thermally stable over the temperature range used for the analysis. GC is not generally applicable for materials with boiling points greater than 300ºC or for materials that decompose at high temperatures.
When combined with appropriate detectors, GC is one of the most sensitive analytical techniques available for the separation, detection, and identification of unknown chemicals, with detection limits typically in the ppm-ppt range, depending on the detector used. Some of the most common detectors used in combination with GC are:
- Mass Selective Detection
- Flame Photometric Detection
- Photoionization Detection
- Electron Capture Detection
- Flame Ionization Detection