Rapid Determination of Total Flavonoids and Extract in the Miao Medicine Toricellia Angulata Oliv.var.intermedia (Harms) Hu by AOTF-Near Infrared Spectroscopy

Samples of the Miao medicine, Toricellia Angulata Oliv.var.intermedia (Harms) Hu, were collected from 48 batches of the freshcrude drug, and the drugs were pretreated by drying at 50℃, powdering to pass through sieve with bore of 0.23 mm and mixing thoroughly to give 48 samples of the drug, numbered from G1 to G48, among which 42 samples (G1 to G42) were taken as calibration set while the remainder 6 samples (G43 to G48) were used as testing set. Initial NIR spectra of the 48 samples were taken by the AOTF-NIR. The intial spectra of samples of the calibration set were pretreated by the 1st order differentiation in the wavelength range of 1 100 to 2 200 nm. The NIR informations of these samples were correlated with the referential data of total flavonoids (TFs) and extract (EXs) in the samples by using the chemometrical soflware, and analytical models for rapid determination of TFs and EXs in the Miao drug were established. Six NIR spectra of a same sample (G1) were taken and treated in the same way as described above to test for precision of the method. Values of RSDs (n=6) found for TFs and EXs were 3.9% and 2.8% respectively. Seven NIR spectra of the sample G1 were taken within the interval of 12 h, and treated in the same way to test for stability of the sample, giving RSDs (n=7) of 2.1% (for TFs) and 2.3% (for EXs). Initial NIR spectra of the 6 samples (G43 to G48) of the testing set were pretreated and predicted by the analytical models, giving values of relation deviations between predicted values and referential values in the range of 1.6% to 6.3% for TFs and 0.60% to 4.3% for EXs, showing good verification results of the established models. It was proved that it takes only 2 to 5 s for analysis of a single sample.