论文部分内容阅读
The present study develops a systematic research for the degradation kinetics of valtrate in artificial intestinal fluid and gastric fluid.HPLC-electrospray tandem mass spectrometry (HPLC-ESI-MSn) was applied to separate the degradation products of valtrate and identify structures of the main degradation products.Samples were separated on an Agilent Extend-C1s by gradient elution using acetonitrile and water-acetic acid (0.25%).Analysis was performed in positive ion mode with 3 000 V of capillary voltage, 40 psi of atomization pressure, 10 L.min-1 dry nitrogen gas velocity and rn/z 100-1000 of scan range.Six degradation products were all identified to own the stem-nucleus structures of baldrinals.Two of them were identified through the reference substances.A HPLC method with isocratic elution using acetonitrile and water (68% ∶ 32%) at 254 nm was established for the determination of content change of valtrate in artificial intestinal fluid and gastric fluid at different time points.The method was validated with good linearity in wide linear ranges (r2 =0.9999), and good intra-day precision (RSD=1.0%).The degradations of valtrate in artificial intestinal fluid and gastric fluid follow pseudo first order kinetic process, the half-life period in artificial gastric fluid is 1.93 hours, and in artificial intestinal fluid is 2.03 hours.This study enriched the knowledge about degradation products of valtrate, revealed the mechanism and rule of the degradation of valtrate in both qualitative and quantitative ways, and provided a theoretical basis for further research.