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.