Column, capillary heat capacity

The typical components of a gas chromatograph are shown in Fig. 32.1. A volatile liquid is injected through a septum into a heated port, which volatilizes the sample. A gaseous mobile phase carries the sample through the heated column, and the separated components are detected and recorded. Two types of columns are available packed and capillary. Open tubular capillary columns offer higher resolution, shorter analysis time and greater sensitivity than packed columns, but have lower capacity for the sample. 

Usually, the stationary phase including CDs in GC was prepared by depositing the modified CDs dissolved in a dimethylformamide solution onto the support (e.g. Chromosorb W) and then evaporated the solvent by vacuum heat-treatment. Some reports described glass or fused silica capillary GC column coated with peralkylated a-, P- and y-CDs dissolved in polysiloxanes. However, the coverage of CD in the surface is limited and results in limited preparative capacity [26]. In addition, the kinetics of inclusion are relatively slow and result in poor peak shape which also hinders the use of CDs as preparative phases. 

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