Spectrofluorimetric Study of an Inclusion Complex of 2-HydroxypropyI-beta-Cyclodextrin with the Antitumour 11-Methyl Benzophenothiazine.Analytical Application to Urine

摘要

The electronic absorption and fluorescence spectral properties of 11-methyl-12H-benzo[a]phenothiazine(11-MeBPHT)were investigated in various media(water,ethanol,beta-cyclodextrin(beta-CD)and 2-hydroxypropyl-beta-cyclodextrin(HP-beta-CD)aqueous solutions).Fluorescence quantum yields were respectively about 20 and 2 times larger in HP-beta-CD and beta-CD than in water.The formation of a 1:1 stoichiometry inclusion complex between 11-MeBPHT and HP-beta-CD(association constant K_f=118 +-3 M~(-1)at 20 deg C)was studied in aqueous medium by fluorescence spectroscopy.Analytical figures of merit were satisfactory for 11-MeBPHT with linear dynamic ranges over at least two orders of magnitude and limits of detection(LODs)between 0.2 and 1 ng/ml according to the medium.An analytical application to the determination of 11-MeBPHT in human urine samples by the standard addition procedure led to satisfactory recovery percentages(91-108%).