X-Ray Fluorescence Spectrometry in Botanical Drugs’ Research - Applications, Methodologies, and Future Perspectives

X-ray fluorescence (XRF) spectrometry is increasingly used in botanical drug research for rapid, nondestructive, multi-elemental analysis. This systematic review examines the principles and applications of major XRF techniques-including energy-dispersive XRF (EDXRF), wavelength-dispersive XRF (WDXRF), total reflection XRF (TXRF), synchrotron radiation XRF (SR-XRF), and portable XRF (pXRF)-in medicinal plant analysis. Key applications include heavy metal safety screening, nutritional profiling, provenance traceability, and authenticity verification, particularly when integrated with chemometrics and machine learning. Advances in sample preparation, matrix effect correction, and speciation analysis are discussed. Emerging interdisciplinary applications, such as metallomics, multidimensional characterization, and green nanomaterial analysis, are also highlighted. Despite challenges with detection limits and matrix effects, ongoing hardware and software innovations continue to expand XRF capabilities. Future integration with spatial metabolomics and multimodal imaging promises to reveal the spatial relationship between inorganic elements and bioactive organic constituents, positioning XRF is one of the pivotal methods for modern botanical drug quality control.