Qualitative and quantitative analysis of Tongren Wuji Baifeng pills by near infrared spectroscopy

Tongren wuji Baifeng pills were analyzed qualitatively and quantitatively by near infrared spectroscopy. Near infrared diffuse reflectance spectra of 98 Tongren Wuji Baifeng pills and 58 Wuji Baifeng pills from different manufacturers were collected. Discriminant analysis was used to distinguish Tongren Wuji Baifeng pills from Wuji Baifeng pills. Similarity match model was built based on the spectra of 70 batches of Tongren Wuji Baifeng pills. By using this model, the similarity match values of other samples were calculated. Quantitative analysis models for total amino acids, paeonin and water content in Tongren Wuji Baifeng pills were developed with partial least square algorithm. No misclassified sample was detected by discriminant analysis. The similarity match model could distinguish different samples. The correlation coefficients of the calibration models were 0.9614, 0.9651 and 0.9910 while the values of root mean square error of prediction were 0.199%, 0.00436% and 0.386%, respectively. The proposed methods are accurate, fast and non-destructive, and can be applied to at-spot detection.