Blood sampling for nicotine pharmacokinetics
SEPARATION
Venous blood samples (2.7 ml) were collected into lithium heparin monovette tubes at − 5 (baseline), 5, 8, 10, 15, 30, and 60 min relative to the first puff of each product use session (either fixed or ad libitum). The collected samples were processed by centrifugation at 1600Plasma nicotine analysis was performed by liquid chromatography with tandem mass spectrometry detection (LC–MS–MS) using the instrument in turbo ionspray, positive ion Multiple Reaction Monitoring (MRM) mode. Two LC–MS–MS systems were used, AB Sciex API4000 and API5000 triple quadrupole atmospheric pressure ionisation mass spectrometers. An automated injection of samples took place using a Shimadzu SIL-20AC autosampler for each system. The API 5000 utilised a Shimadzu LC-20AD pump and the API4000 a Shimadzu LC-20AB pump. LC–MS–MS separation was performed using a Betasil-Silica-100 column using an isocratic method. The following MRM transitions were monitored: nicotine: 