A study on the identification of habitats and determination of sulfur dioxide residue of Radix Astragali by UV-vis-SWNIR diffuse reflectance spectroscopy

The feasibility of identifying habitat of sulfur fumigated Radix Astragali and of determining its sulfur dioxide residue using UV-vis and short wave near-infrared diffuse reflectance spectra coupled with chemometrics was first investigated. The results show that by using UV-vis-SWNIR DRS combined with PCA, the habitat of Radix Astragali is identified definitely, whether it is sulfur-fumigated, or not sulfur-fumigated; after waveband selection, SG smoothing and excluding outliers, PLS modelling results were improved with a R2 of 0.9238, 0.9104 and 0.9322 for calibration set, cross validation set and prediction set, respectively. A convenient and rapid method for identification of the habitat of sulfur fumigated Chinese herbal medicines and determination of sulfur dioxide residue by UV-vis-SWIR DRS was proposed.