Exploring the capabilities of HERFD-XAS to resolve Cd speciation in environmental samples

Cadmium is toxic at low concentrations for most forms of life. Food is the main route of exposure to cadmium for the general population. Chocolate is a Cd contributor in human diet. Research is needed to understand the mechanisms involved in Cd accumulation in this crop, to produce beans with less Cd. Cd speciation in plant organs is challenging because of the low Cd concentrations (0.5 to 5 mg kg-1 FW). HERFD-XAS is a promising technique, and has not been used for Cd so far. We propose a Cd LIII-edge HERFD-XAS study on Cd model compounds to build a database and evaluate the potential of this method to distinguish Cd species, and assign spectral features to structural parameters. This study will be a first step of a proof of concept of the interest of HERFD-XAS to study Cd in diluted environmental samples.

镉（Cadmium）在低浓度条件下即可对绝大多数生命形式产生毒性。普通人群接触镉的主要途径为食物。巧克力是人类膳食中镉的重要来源之一。当前仍需开展相关研究以阐明该作物中镉积累的作用机制，进而培育出镉含量更低的籽粒。由于植物器官内镉浓度极低（0.5至5 mg·kg⁻¹ 鲜重（Fresh Weight）），对其镉形态进行分析颇具挑战。高能量分辨荧光检测X射线吸收谱（HERFD-XAS）是一项极具应用前景的技术，但目前尚未将其用于镉的相关研究。我们提出针对镉模型化合物开展镉LⅢ边HERFD-XAS研究，以构建相关数据库并评估该方法区分镉形态的潜力，同时实现光谱特征与结构参数的关联。本研究将作为验证HERFD-XAS用于稀释环境样品中镉研究可行性的概念验证首步工作。