Luisa (ESR 3) worked in 7 photoreduction experiments with different conditions to study Hg and C stable isotopes. The relevant results were presented at the Goldschmidt conference in June under the title “ Carbon and mercury stable isotopes fractionation during aqueous MeHg photoreduction” in the section “Towards a better understanding of mercury dynamics within and between land, atmosphere and ocean systems to support the effectiveness evaluation of the Minamata Convention”. Still, some clues are missing and the C isotope study resulted be more complicated than expected initially. To finish the photo degradation study and complete the C isotope analysis, 3 more experiments were planned for the months of August and September. And then that’s it, no more colored waste experiments.
For the month of November and with great excitement, Luisa is also getting ready for 1 month secondment in Sweden at the Stockholm University, with Dr. Sofy Jonsson and Sonja Gindorf (ESR7). This time to work, learn and explore the abiotic methylation of mercury under lab controlled condition instead of the degradation of the MeHg. Which are the best abiotic methylation methods? How to avoid the formation of Dimethylmercury (DMHg)? It’s DMHg a compound of interest in our research? Could we find a way to measure C isotopes in DMHg? How does the isotopic composition of C change from the reactants to the final product? Many more questions to answer in the search for fingerprints to point out the MeHg origin.
