Basic Principle of GC–sample vaporized by injection into a heated system, eluted through a column by inert gaseous mobile phase and detected.
Three types: gas – solid chromatography, gas – liquid, gas – bonded phase.
Gas chromatography quickly gained general acceptance because it was introduced at the time when improved analytical controls were required in the petrochemical industries, and new techniques were needed to overcome the limitations of old laboratory methods. Nowadays, gas chromatography is a mature technique, widely used worldwide for the analysis of almost every type of organic compound, even those that are not volatile in their original state but can be converted to volatile derivatives.
Basic GC Chromatography Theory, Concepts and Applications
Gas chromatography is a separation technique in which the components of a sample partition between two phases:
1. The stationary phase.
2. The mobile gas phase.
According to the state of the stationary phase, gas chromatography can be classified in gas-solid chromatography (GSC), where the stationary phase is a solid, and gas-liquid chromatography (GLC) that uses a liquid as stationary phase. GLC is to a great extent more widely used than GSC.
Advantages of GC Chromatography
• Due to its high efficiency, GC allows the separation of the components of complex mixtures in a reasonable time.
• Accurate quantitation (usually sharp reproducible peaks are obtained)
• Mature technique with many applications notes available for users.
• Multiple detectors with high sensitivity (ppb) are available, which can also be used in series with a mass spectrometer since MS is a non-destructive technique.