Abstract: An ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method for the determination of mitomycin C (MMC) in rabbit plasma was established. The blank rabbit plasma sample solutions added with mitomycin C and triamcinolone acetonide (internal standard, IS) were prepared. The solutions containing MMC and IS were extracted from the plasma with ethyl acetate using liquid-liquid extraction method. A Hypersil Gold C18 column (50 mm×2.1 mm, 1.9 μm) was employed and the column temperature was set at 35 ℃. The isocratic elution of methanol and 0.1% (v/v) formic acid aqueous solution as mobile phase was performed at a flow rate of 0.2 mL/min, and a rapid separation was completed within 3 min. The electrospray was operated in the positive ionization mode and the MMC and IS were identified in selected reaction monitoring (SRM) mode. The monitoring ions of MMC and IS were m/z 335.2→242.2 and m/z 435.2→397.3/415.2, respectively, which were used to qualify and quantify the targets by the method of matrix-matched standard solution. The calibration curve showed good linearity within the mass concentrations of 1 to 1000 μg/L (r=0.9978, weighting: 1/x2). The limit of detection (S/N=3) was 0.2 μg/L. The recoveries were from 85% to 115% at the spiked levels of 1, 5, 100 and 800 μg/L, and the relative standard deviations (RSDs) of intra- and inter-day were both less than 15%. The method can meet the determination requirements of biological samples, and can be used for the determination of mitomycin C in rabbit plasma after the administration of mitomycin C. The method is selective, sensitive, convenient, rapid and reproducible in the determination of mitomycin C, and also can be used for the pharmacokinetics research of mitomycin C in plasma.

Key words: electrospray ionization (ESI), mitomycin C, New Zealand big white rabbit, plasma, ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS)