This paper describes the binding of Calcofluor, a fluorescent probe, to oat beta-glucan in buffer solutions. The binding equilibrium constant (K), the total number of binding sites per beta-glucan molecule (N), and the average binding number of Calcofluor per beta-glucan molecule (n) were determined by UV spectroscopic method. The results indicate that the association of Calcofluor and beta-glucan is driven by both enthalpy and entropy and that the process involves hydrogen bonding, van der Waals forces, and hydrophobic interaction. Higher buffer concentration and NaCl facilitate the binding of Calcofluor to beta-glucan. The adsorption isotherm fits a Langmuir model quite well.

SummaryTwo new cyclodextrin (CD) derivatives, heptakis{2,6-di-were synthesized and coated on fused-silica capillary columns. Their chromatographic characteristics, including column efficiency, polarity, selectivity and phase transition were studied and compared with similar I~-CD stationary phases. It was found that the heterocycle group has a significant effect on the selectivity of the CD stationary phases. Both stationary phases can be successfully used to separate many di-and trisubstituted benzene positional isomers and show stronger separation ability in separating low-polarity benzene positional isomers than other ~-CD stationary phases.

SummaryA new resorcarene derivatives, ethylhexylresorcarene, was synthesized and used as stationary phase in opentubular (capillary) columns. It was combined with heptakis(2,6-di-O-pentyl-3-O-trifluoroacetyl)-~-CD and coated on fused-silica capillary tubes. By studying the chromatographic properties of the mixed stationary phase and its selectivity for different isomers, as well as comparing with the resorcarene and the CD used as individual stationary phases, a synergistic effect was observed on the mixed stationary phase.

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