Recientemente se ha publicado un nuevo trabajo de investigación, liderado por nuestro compañero Aridane González, en la revista Science of the Total Environment (JCR, Q1). Este trabajo se ha titulado: Influence of strong iron-binding ligands on cloud water oxidant capacity.
En este trabajo se demuestra la presencia de ligandos orgánicos, con capacidad para complejar al Fe, en agua de nubes muestreada en Puy de Dome (Francia). Estos resultados son de especial interés para entender el ciclo biogeoquímico del Fe en el planeta, pero también para entender mejor la química atmosférica ya que la presencia de estos ligandos hace que se mejoren los modelos químicos existentes.
Este es el resumen original del trabajo:
Iron (Fe) plays a dual role in atmospheric chemistry: it is involved in chemical and photochemical reactivity and serves as a micronutrient for microorganisms that have recently been shown to produce strong organic ligands. These ligands control the reactivity, mobility, solubility and speciation of Fe, which have a potential impact on Fe bioavailability and cloud water oxidant capacity.
In this work, the concentrations of Fe-binding ligands and the conditional stability constants were experimentally measured for the first time by Competitive Ligand Exchange-Adsorptive Cathodic Stripping Voltammetry (CLE-ACSV) technique in cloud water samples collected at puy de Dôme (France). The conditional stability constants, which indicate the strength of the Fe-ligand complexes, are higher than those considered until now in cloud chemistry (mainly Fe-oxalate). To understand the effect of Fe complexation on cloud water reactivity, we used the CLEPS cloud chemistry model. According to the model results, we found that Fe complexation impacts the hydroxyl radical formation rate: contrary to our expectations, Fe complexation by natural organic ligands led to an increase in hydroxyl radical production. These findings have important impacts on cloud chemistry and the global iron cycle.
Graphical abstract from Gonzalez et al., 2022