Objective To establish a simple high-performance liquid chromatography-tandem mass spectrometry(HPLC-MS) system for determination of capsaicin in rat plasma.Methods Rat plasma(100 μl) was extracted with mixed solvent(ethyl acetate∶acetone 85∶15) after addition of 50 ng/ml internal standard,and analyzed by Agilent 6460 Triple Quadrupole LC/MS system.The detection was performed with multiple reactions monitoring using electrospray ionization.The precursor/product ion transitions were monitored at m/z 306→137(...