Laser ablation ICP-OES combined to carbon paste electrode voltammetry for monitorization of electroactive species in fluvial deposits

Abstract

Some of the most favorite settlements for humans are fluvial terraces due to the proximity to water supplies. Thus, these geological formations are highly exposed to anthropogenic effects. Additionally, their geomorphologic evolution is also related to climatic conditions. The most powerful techniques for dating terrace sediments are based on rock magnetism in combination with stratigraphic studies. Here, the presence of ferromagnetic compounds is used to obtain geochronological information. The knowledge of the chemical composition, especially about those species that show magnetic properties, provides complementary information to the acquired by archaeomagnetism techniques, about the magnetic components in the samples. The objective of this study is to set up a strategy to investigate iron and titanium compound in terms of element composition and oxidation state distribution in terrace sediments from the Duero basin in Spain. Multielement analyses were carried out by Laser Ablation ICP-OES in order to avoid sample digestion. Accuracy was assessed by analysis of several certified reference materials. Iron and titanium electrochemistry was performed by Carbon Paste Electrode Cyclic Voltammetry which allowed us to identify the presence of magnetite and ilmenite in samples additionally to the Fe(II)/Fe(III) system using only a small amount of sample and avoiding any further chemical Treatment.