1. Department of Chemistry, University of Girona, Campus Montilivi, E-17071 Girona, Spain, FEMAN Group, IN2UB, Applied Physics and Optics Department, Physics Faculty, University of Barcelona, Martí i Franquès 1, E-08028 Barcelona, Spain, and Environmental Chemistry Department, Instituto de Diagnóstico Ambiental y Estudios del Agua, Consejo Superior de Investigaciones Científicas (IDAEA-CSIC), Jordi Girona 18-26, E-08034 Barcelona, Spain