Determination of adulteration in Echinacea spp. by principal component analysis of UV spectra

Ultraviolet (UV) spectroscopy was used to determine adulteration in Echinacea spp. Authenticated samples of Echinacea angustifolia and Echinacea purpurea roots were used to generate a predictive model using a Principal Component Analysis (PCA) algorithm. Adulterated and unadulterated test samples were used to show the effects of applying the model. Our results show that PCA is effective for distinguishing species of Echinacea, as well as determination of adulteration levels in Echinacea samples up to at least 25% admixture.

Fig. 1: PCA of UV spectra of authenticated samples of E. angustifolia and E. purpurea showing 95% confidence intervals.