Abstract:To establish an identification method for Radix Fici hirtae (RFH)-a homology of medicine and food—and its adulterants by using three-dimensional fluorescence spectroscopy, the effect of β-cyclodextrin (β-CD) on the enhancement of the fluorescence intensity of RFH extracts was studied. A new supramolecular host-guest compound was formed by β-CD and RFH extracts in a weak-acid medium, and the fluorescence intensity of RFH extracts was improved by an order of magnitude, creating conditions for the determination of the fluorescence of RFH. The influences of mass ratio of RFH to β-CD [m(RFH):m(β-CD)], pH value of the sensitization medium, and sensitization time and temperature on the fluorescence spectra of the RFH/β-CD system were assessed. The optimal sensitization conditions were determined through orthogonal test, and they were as follows: m(RFH):m(β-CD)= 1:10, sensitization time=1 h, pH value= 4.25, and temperature= 60 ℃. Under the optimized sensitization conditions, the characteristics of three-dimensional fluorescence contour spectra, characteristic fluorescence peak position, and fluorescence intensity were used as references for the fingerprint identification of RFH. A method to identify RFH using β-CD-sensitized fluorescence spectroscopy was established. This method has a high sensitivity and good reproducibility and can be applied for rapid identification of RFH and its adulterants.
