On-line solid-phase extraction with ultra performance liquid chromatography and tandem mass spectrometry for the detection of nicotine, cotinine and trans-3'-hydroxycotinine in urine to strengthen human biomonitoring and smoking cessation studies., De Cremer, Koen, Van Overmeire Ilse, and Van Loco Joris , J Pharm Biomed Anal, 2013 Mar 25, Volume 76, p.126-33, (2013)