Rapid screening and identification of polar constituents from Brazilian Arnica lychnophora sp. by LC-UV/DAD-ESI-MS and LC-UV/DAD-ESI-MS/MS analysis - Moraes, Solange Leite de; Gregório, Luiz Elídio; Tomaz, José Carlos; Lopes, Norberto Peporine (Chromatographia, 2009)