Simultaneous analysis of tramadol, O-desmethyltramadol, and N-desmethyltramadol enantiomers in rat plasma by high-performance liquid chromatography-tandem mass spectrometry: Application to pharmacokinetics - Godoy, Ana Leonor Pardo Campos; Moraes, Natália Valadares de; Martinez, Edson Zangiacomi; Carvalho, Teresa Maria de Jesus Ponte; Marques, Maria Paula; Lanchote, Vera Lúcia (Chirality, 2011)