Direct characterization of aqueous extract of Hibiscus sabdariffa using HPLC with diode array detection coupled to ESI and ion trap MS - Rodríguez-Medina, I C; Beltrán-Debón, R; Molina, V M; Alonso-Villaverde, C; Joven, J; Menéndez, J A; Segura-Carretero, A; Fernández-Gutiérrez, A (J Sep Sci, 2009)