β-环糊精增敏三维荧光法鉴别真伪五指毛桃

Identification of Radix Fici hirtae and Its Adulterants by β-cyclodextrin-sensitized Three-dimensional Fluorescence Spectroscopy

摘要:

为建立药食同源五指毛桃真伪品的三维荧光快速鉴别方法，研究β-环糊精(β-CD)对五指毛桃提取液的荧光增强作用。五指毛桃提取液在弱酸性条件下与β-CD形成主客体超分子化合物，提高了约一个数量级的荧光强度，为五指毛桃的荧光测定创造了条件。考察了五指毛桃与β-CD质量比m[(五指毛桃):m(β-CD)]、敏化体系pH值、敏化时间和温度等因素对五指毛桃/β-CD体系荧光光谱的影响，正交实验确定了敏化最佳条件，即m(五指毛桃):m(β-CD)=1:10，敏化时间1 h，pH值为4.25，敏化温度60 ℃。在优化β-CD敏化条件下，三维荧光等高线图谱特征、荧光峰位置、强度作为五指毛桃指纹识别的参考依据。建立了β-CD敏化三维荧光光谱法鉴定五指毛桃的方法，灵敏度高，重现性好，可应用于五指毛桃的真伪品的快速鉴别。

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.