1. Community Reference Laboratory (DG SANCO) for Residues of Pesticides in Fruits and Vegetables, Pesticide Residue Research Group, Department of Hydrogeology and Analytical Chemistry, University of Almería, 04120 La Cañada de San Urbano, Almería, Spain, and Analytical Chemistry Research Group, Department of Physical and Analytical Chemistry, University of Jaén, 23071 Jaén, Spain