ABSTRACT
Chromatography covers the separation techniques that involve the repeated distribution or partitioning of the analytes between two different phases: the stationary phase and the mobile phase. The basic gas chromatograph consists of the carrier gas supply, the inlet or injector, the column, the detector, and the data system. In gas–solid chromatography, the stationary phase is an uncoated solid, which may be a simple adsorbent, such as alumina and silica, or a porous solid, such as a molecular sieve. In gas chromatography, a supply of carrier gas is required as the mobile phase to transfer the samples from the injector, through the column, and into the detector. Samples in the form of a liquid are usually injected into the gas chromatograph using a microsyringe through a rubber or silicone septum. In the modern gas chromatograph, the carrier gas flow during analysis can be changed by gradually increasing the inlet pressure.
