1. Department of Chemistry, University of Girona, Campus Montilivi, 17071 Girona, Spain
2. Centro de Fisica Atomica, Universidade de Lisboa, Av. Prof. Gama Pinto, 2, 1649-003 Lisbon, Portugal
3. Laboratory of X-ray Analytical Applications, Institute of Earth Sciences “Jaume Almera”, CSIC, Solé Sabarís s/n, 08028 Barcelona, Spain