Determination of cyclodextrin formation constants using dynamic coupled-column liquid chromatography

Dynamic coupled-column liquid chromatography is used to determine both aqueous solubilities and cyclodextrin inclusion complex formation constants for a series of polynuclear aromatic hydrocarbons (PAHs). This method Is based on the increase In solubility afforded by cyclodextrlns upon complexation. Formation constant (Kf) values are determined by using α-, β-, and γ-cyclodextrlns at various temperatures. The relative precision of the calculated Kf values is best for cyclodextrin/PAH complexes with large formation constants. The calculated solubilities are comparable to literature values, and in most cases, formation constant data are reproducible within 10%. The resulting Kf values confirm that the formation of Inclusion complexes is based on the relative sizes of host and guest molecules.