Thermoanalytical method for studying the guest content in cyclodextrin inclusion complexes

摘要

The interaction of cypermethrin with beta-cyclodextrin was investigated using different (coprecipitation, suspension, kneading and,melting in solution') complexation methods and qualifying the resulted complexes by UV-spectrophotometry, thermal methods (TG, DTG and DSC) and X-ray powder diffraction. The total guest content of complexes can be measured by UV-spectrophotometry in aqueous ethanol solution, while the uncomplexed guest fraction of samples can be determined by DSC based on a previous calibration curve, which was found between the melting enthalpy change of cypermethrin and the guest content of physical mixture samples. The combination of both analytical methods enables the determination of really complexed guest content.