On-line identification of tropane alkaloids from Erythroxylum vacciniifolium by liquid chromatography-UV detection-multiple mass spectrometry and liquid chromatography-nuclear magnetic resonance spectrometry - Zanolari,B.; Wolfender,J.L.; Guilet,D.; Marston,A.; Queiroz,E.F.; Paulo,M.Q. (J Chromatogr A, 2003)