Characterization of nine traditional Chinese plant extracts with specific acid dissociation constants by UV-Vis spectrophotometry

Abstract

A UV-Vis spectrophotometric method for characterization of plant extracts with specific acid dissociation constants was developed and nine traditional Chinese plant extracts were used in the analysis workflow. The ionization of plant extracts gave intensive pH-dependent spectral shifts and their spectral changes differed between wavelength ranges. The simulation with the one-step and two-step ionization processes showed that the acid dissociation constants distributed steadily at some wavelength ranges. These specific acid dissociation constants might be used as markers for characterization of plant extracts. This study suggests that the proposed method has potential applications for quality assessment and mass quality control of plant extracts used in food and pharmaceutical industries.