Synchrotron-radiation X-ray absorption spectroscopy (XAS) is a direct method for speciation analysis with atomic resolution, providing information about the local chemical environment of the probed element. This article gives an overview of the basic principles of XAS and its application to element speciation in biomedical research. The basic principle and experimental modalities of XAS are introduced, followed by a discussion of both its limitations, such as beam damage or detection limits, and practical advices to improve experiments. An updated review of biomedical studies involving XAS published over the last 5 years is then provided, paying special attention to metal-based drug biotransformation, metal and nanoparticle toxicology, and element speciation in cancer, neurological, and general pathophysiology. Finally, trends and future developments such as hyphenated methods, in situ correlative imaging and speciation, in vivo X-ray Absorption Near Edge Spectroscopy (XANES), full-field XANES, and X-ray Free Electron Laser (XFEL) XAS are presented.

同步辐射X射线吸收光谱（XAS）是具有原子分辨率的形态分析的直接方法，可提供有关所探测元素的局部化学环境的信息。本文概述了XAS的基本原理及其在生物医学研究中元素形成的应用。介绍了XAS的基本原理和实验方式，然后讨论了XAS的局限性，例如光束损伤或检测极限，以及改进实验的实用建议。然后提供了最近5年中涉及XAS的生物医学研究的最新综述，并特别关注了基于金属的药物的生物转化，金属和纳米毒理学，以及癌症，神经病学和一般病理生理学中的元素形态。最后，介绍了趋势和未来的发展，例如联用方法，原位相关成像和物种形成，体内X射线近边缘吸收光谱（XANES），全场XANES和X射线自由电子激光（XFEL）XAS。