Thermodynamic investigation on As(III) and As(V) in aqueous solution and extraction from natural water samples by Polymer Inclusion Membranes (PIMs)

The thermodynamic behaviour of As(III) and As(V) was studied in aqueous solution. In the first case, the interaction with ligands of biological and environmental interest was investigated at different experimental conditions and, sometimes, by employing molecular dynamics simulations in order to gain information about the coordination mode. As regards As(V), the interaction of arsenate with alkaline earth metal cations and trivalent metal cations was evaluated. In order to determine the metalloid in natural waters, a combined methodology featured by the extraction of arsenic by means of Polymer Inclusion Membranes (PIMs) and the detection by Energy Dispersive X-Ray Fluorescence (EDXRF) was developed. This method also proved useful to perform speciation analysis, since it was able to discriminate between the two chemical forms, namely As(III) and As(V).