During his thesis, which began under the supervision of Cédric Garnier, Nicolas Layglon was able to carry out several sediment core sampling missions. These sediment cores were sliced every two centimetres to characterise the diagenetic sequence and quantify the concentrations of dissolved metals in the pore water at high resolution. In addition, the total metal content and the distribution of the metal on the different carrier phases were assessed. The determination of NH4+, SO42, PO43-, SiO4 and HS- was carried out spectrophotometrically, while the concentration of metals was quantified by ICP-MS. In addition, laboratory experiments in which sediments were brought into contact with seawater revealed the kinetics and remobilisation amplitudes of trace metals in seawater. I assessed the concentration of dissolved metals using DPASV (for Cu, Cd, Pb and Zn), DPCSV (for Co and Ni) and ICP-MS (for a wider range of metals). Nicolas also had the opportunity to work on determining the concentration of As (III) and (V) in seawater using PSA.
(potentiometric stripping voltammetry) using gold micro-wires.
Nicolas is starting a post-doc at the University of Geneva in the Department of Analytical Chemistry and Inorganic Chemistry. The aim of this post-doc is to characterise and optimise nanostructured gold microelectrodes interconnected on gel for in situ measurements of inorganic arsenic (As (III), As (V)) and mercury (Hg (II)) in aquatic systems.
The use of microelectrodes will be validated in the field, by comparing these new analysis tools in coastal areas with established laboratory techniques.
Atlantic and/or Mediterranean. The field application of these microelectrodes will be used to study the bio-geochemical cycles of target species and assess their potential ecotoxicological impact.
He has also set up a project to determine the speciation of ETMs in sediment cores, using pipers and voltammetric techniques. In addition, the change in speciation of these ETMs during resuspension events will be studied in this project proposed to the Marie Skłodowska-Curie Actions Individual Fellowship. The results of this call for proposals will be published in February 2021.