Exploring ED-XRF and ATR-FTIR spectroscopic techniques in medicinal plant research: A pilot study with Scutellaria...

The study presents the application of Energy-Dispersive X-ray Fluorescence (ED-XRF) and Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy (ATR-FTIR) in analyzing the quality and variability of medicinal plants, with a focus on Scutellaria baicalensis (SB) roots. SB is widely used in medicine due to its pharmacological and biological properties. Therefore, an appropriate analytical approach is essential for determining its detailed composition. The aim of this study is to develop reliable, non-destructive analytical methods for monitoring both the elemental and organic profiles of plant materials. Harvested in spring, summer, and autumn, SB roots were subjected to various processing techniques, including different drying methods (oven drying and lyophilization) and extraction methods (maceration, reflux extraction, and ultrasound extraction). ED-XRF provided detailed insights into both macro- and micro-elemental content, revealing that seasonal variations and processing methods significantly influence the elemental composition of the roots. ATR-FTIR semi-quantitative analysis revealed seasonal variation in phytochemical content, with the most favorable presence of active compounds observed in autumn. Advanced chemometric tools (including PCA and two-trace two-dimensional (2T2D) correlation spectroscopy) highlighted differences in chemical profiles based on harvesting time and preparation method. This pilot study demonstrates the effectiveness of combining ED-XRF and ATR-FTIR as powerful tools for evaluating the quality of medicinal plants. The findings suggest that both seasonal harvesting and appropriate sample preparation play crucial roles in maintaining the optimal chemical profile of the samples. The proposed approach can be widely applied in medicinal plant research to monitor the presence, concentrations, and variability of herbal ingredients.