Models Based on Near-Infrared Spectroscopy for Rapid Prediction of Hyperin and Isoquercitrin in Miao Medicine of Leaves of Toricellia Angulata Oliv.var.intermedia (Harms) Hu

Quantitative analysis model based on near-infrared spectroscopy was developed for rapid prediction of hyperin and isoquercitrin in Miao medicine of the leaves of Toricellia Angulata Oliv.var.intermedia (Harms) Hu. After the sample was extracted with methanol by reflux in a water bath, the near-infrared spectrometer was used to collect the spectral information in the wavelength range of 1 100-2 300 nm by transmission method. Meanwhile, hyperin and isoquercitrin were determined by HPLC, and the results were used as reference values. The original spectra of hyperin and isoquercitrin were pretreated by the transformation SNV-smoothing and S-G first derivative. The quantitative analysis models of hyperin and isoquercitrin were constructed by partial least squares method (PLS) at 1 100-2 300 nm and 1 100-1 400 nm, respectively. Correlation coefficient, root mean square error of correction (RMSEC), root mean square error of prediction (RMSEP) and relative prediction deviation (RSEP) were used to investigate the performance of the model. The results showed that RMSEC, RMSEP and RSEP values of quantitative analysis model of hyperin were 0.241 4, 0.270 5 and 0.177 5, respectively, and correlation coefficient was 0.913 6. RMSEC, RMSEP and RSEP values of quantitative analysis model of isoquercitrin were 0.079 1, 0.020 8 and 0.033 9, respectively, and correlation coefficient was 0.907 7. The established quantitative analysis models of hyperin and isoquercitrin were used to predict the contents of hyperin and isoquercitrin in the validation set samples. The relative errors between predicted values and reference values were found in the ranges of -2.8%-2.9% and -5.1%-5.9%, respectively. After six repeated analysis of the actual samples, RSDs of the predicted values of hyperin and isoquercitrin were 2.7% and 3.3%, respectively. After placing the sample solution for 0, 1, 2, 3, 6, 12 h, RSDs of the predicted values were 2.9%, 3.4%, respectively.