[Study on measuring host-guest ratio of inclusion compound of beta-CD-permethrin by IR]

Permethrin is one of the agrochemicals used in tea gardens currently with the characteristic of being easily decomposed in light. Permethrin with beta-cyclodextrin(CD) made into Inclusion Compound (IC) can increase its stability and reduce dosage to remain on the tea. Host/guest ratio is one of the important parameters of IC. The IC of permethrin with beta-CD was prepared by means of liquid phase method and characterized by using IR. The result of the IR proves that the characteristic absorption peaks of the host and guest are not changed by forming their IC. The host/guest ratio of the IC measured by IR is 1:1. Potassium sulfocyanate (KSCN) was chosen as an inside mark material, because it has only one strong absorption peak at 2100 cm(-1) and the peak was chosen as a quantitative peak of KSCN. The peak at 580 cm(-1) is the characteristic absorption of the wreath vibration of beta-CD and was chosen as a quantitative peak of beta-CD. KSCN and beta-CD were mixed with a certain quantity ratio and the mixture was analyzed by IR. The work curve of IR was established. A kind of new experimental method of measuring host/guest ratio of the IC was provided.