1. Mass Spectrometry and Pharmacology Laboratory, A. Meyer Children’s Hospital Pediatric Neurology Unit and Laboratories, Department of Pharmacology, University of Florence, Florence, Italy, Applied Biosystems, Via Tiepolo 18, 20052 Monza, Italy, Pediatric Neurology Unit and Laboratories, A. Meyer Children’s Hospital, Florence, Department of Neurosciences, University of Florence, Florence, Italy, and Department of Pediatrics, University of Florence, Viale Pieraccini 24, 50139 Florence, Florence, Italy