Peralkylated-beta-cyclodextrin used as gas chromatographic stationary phase prepared by sol-gel technology for capillary column

For the first time, three peralkylated-beta-cyclodextrins (beta-CD), permethylated-beta-CD, perethylated-beta-CD and perpentylated-beta-CD, were coated onto the fused-silica capillary by sol-gel method with simplicity and rapidity. Multiple steps in conventional column preparation technology were avoided. Also, these new columns demonstrated many inherent advantages, the main being the outstanding thermal stability (up to 300 degrees C), high number of theoretical plates, excellent column-to-column and run-to-run reproducibility, and pronounced selectivity for positional isomers and enantiomers. Using n-tridecane as a test reagent (k = 4.18), an efficiency value of 3520 theoretical plates/m was obtained on a sol-gel perpentylated-beta-CD capillary column (15 m x 0.25 mm I.D.). On the basis of the results, we proposed that the peralkylated-beta-CD, which has no terminal hydroxyl group, is encapsulated in the sol-gel network and the whole matrix is chemically bonded to the surface of the fused-silica tubing.