Study on the inclusion interactions of β-cyclodextrin and its derivative with dyes by spectrofluorimetry and its analytical application

The inclusion interactions of β-cyclodextrin (β-CD) and hydroxypropyl-β-cyclodextrin (HP-β-CD) with dyes were developed by spectrofluorimetry, and the inclusion constants of inclusion complexes were determined by direct fluorescence technique. The main factors (the host molecule, the guest molecule, and the pH) for the inclusion interaction were discussed in detail. At the same time, the inclusion interaction of HP-β-CD and vitamin B6 (VB6) was investigated with the competitive fluorescence inclusion method and the inclusion constant of HP-β-CD and vitamin B6 (VB6) was obtained by indirect fluorescence technique. On the basis of the linear relationship between the change of fluorescence intensity (ΔF) and the concentration of VB6, a competitive fluorescence inclusion method was used to the determination of VB6. The method has been successfully applied to the analysis of VB6 in synthetic samples, tablets and injections with satisfactory results.