Rapid and nondestructive authentication of Glehniae Radix and detection of adulteration using near-infrared spectroscopy and chemometrics

To establish a rapid, nondestructive method for identifying authentic and adulterated Glehniae Radix samples via near-infrared (NIR) spectroscopy combined with chemometrics. NIR spectra of authentic Glehniae Radix, counterfeit samples, and adulterated mixtures were acquired using the integrating sphere diffuse reflection method. Discriminant models were established by combining principal component analysis (PCA) and partial least squares–discriminant (PLS-DA) analysis with various spectral preprocessing techniques—including differentiation, multiplicative scatter correction (MSC), and standard normal variate transformation (SNV)—to predict the authenticity and adulteration of Glehniae Radix medicinal materials. The predictive performance of these models was validated using external samples. The proposed method achieved 100% identification accuracy in distinguishing Glehniae Radix from counterfeit species (Adenophora tetraphylla, Chuanminshen violaceum, and Ferula bungeana) and detecting adulterated samples across blending ratios of 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, and 90%. This method demonstrated high predictive accuracy, stability, analysis speed, and nondestructive sample processing. Moreover, it provided a strong foundation for establishing online analytical techniques to authenticate Glehniae Radix and detect adulteration.