Preparation and Separation Behaviors of New Gas Phase Capillary Columns with β-Cyclodextrin Derivatives

A new capillary column was prepared by statically coating hydroxypropyl--cyclodextrin (HP--CD) onto inner surface of fused capillary and its theoretical plate number is measured to be 2337 /m according to the literature method, which is close to a commercial gas phase capillary column coated with heptakis-(2, 6-O-dipentyl-3-O-trifluoro acetyl)--cyclodextrin (denoted as DP-TFA--CD). Separations of some benzene positional isomers, namely, nitrotoluene, nitrochlorobenzen, dichlorobenzene, xylene, and dimethyl phthalate, were investigated on these two capillary columns in gas chromatography. The HP--CD and DP-TFA--CD columns show good separation abilities toward five selected analytes. Separation factors for dichlorobenzene on the HP--CD column are 1.28 and 1.13, respectively, which are better than the other.