| Abstract: | Heptakis(2,6-di-O-methyl-3-O-trifluoroacetyl)-?-cyclodextrin has been chemically bonded to a polydimethylsiloxane via an octamethylene spacer and subsequently immobilized on to the surface of fused silica capillaries, the first time a cyclodextrin derivative with mixed substituents has been immobilized in this way. The enantioselectivity of the new chiral stationary phase has been investigated as a function of the cyclodextrin content. It was found to be higher than that reported for heptakis (2,6-di-O-methyl-3-O-trifluoroacetyl)-?-cyclodextrin or hepta-kis(2,6-di-O-methyl-3-O-acetyl)-?-cyclodextrin dissolved in polysiloxane (e.g. OV-1701). The degree of immobilization was over 90 %. The temperature stability is, however, inferior to that of Chirasil-Dex (a permethylated cyclodextrin): the maximum operating temperature is approximately 200 °C. |
