Optimization and validation of a liquid chromatography-tandem mass spectrometry method for the simultaneous quantification of nicotine, cotinine, trans-3'-hydroxycotinine and norcotinine in human oral fluid

Optimization and validation of a liquid chromatography-tandem mass spectrometry method for the simultaneous quantification of nicotine, cotinine, trans-3'-hydroxycotinine and norcotinine in human oral fluid