A new method for qualitative and quantitative analysis of Rhodobryum giganteum by using the nonlinear oscillating chemical was established for improving the quality control standard of R. giganteum. Its potential(E)/time(t) curve was recorded by electrochemical workstation in the oscillation reaction system of BrO~-_3-Ce(SO_4)_2-H_2SO_4-malonic acid/tartaric acid. The nonlinear oscillating chemical fingerprints were investigated for repeatability, and it was found that the RSD values of the four characteristic parameters of R. giganteum were less than 4.1%, indicating a good repeatability and high precision of this experiment. After optimizing the experimental parameters such as particle size, rotation speed and temperature, a new method based on nonlinear oscillating chemical was used for qualitative and quantitative analysis of R. giganteum. The results showed that there was a good linear relationship between the induction time/the period of oscillation and the dosage of herbs(0.1-1.1 g), with the relative coefficients of 0.978 and 0.975, respectively. Besides, the highest potential showed a nonlinear relationship with the dosage of herbs, with the relative coefficient of 0.999. This method was also used to discriminate the R. giganteum and R. roseum. They were similar in appearance, but their fingerprints were quite different. Independent sample t test results showed that there were significant differences in the oscillation time, the maximum amplitude and the induction time, providing a basis for the identification of the basic sources of Herba Rhodobryi Rasei.
Keywords: Rhodobryum giganteum; nonlinear oscillating chemical fingerprint; qualitative analysis; quality control; quantitative analysis.