1.Simultaneous determination of fraxin and its metabolite, fraxetin, in rat plasma by liquid chromatography-tandem mass spectrometry and its application in a pharmacokinetic study.
Wang H1, Xiao B1, Hao Z1, Sun Z2. J Chromatogr B Analyt Technol Biomed Life Sci. 2016 Apr 1;1017-1018:70-4. doi: 10.1016/j.jchromb.2016.02.030. Epub 2016 Feb 23.
For the first time, a rapid and sensitive high-performance liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed for the simultaneous determination of fraxin and its metabolite, fraxetin, in rat plasma, using esculin as the internal standard (IS). The plasma samples were precipitated with methanol before separation on an Nova-Pak C18 column (150mm×3.9mm, 3μm) using a mobile phase consisting of 0.1% formic acid and methanol (55:45) at a flow rate of 0.8mL/min. The analytes were detected by multiple reaction monitoring in the negative ion mode with the mass transitions at m/z 368.9→ m/z 191.9 (fraxin), m/z 206.9→ m/z 191.8 (fraxetin) and m/z 339.0→ m/z 176.9 (esculin, IS). The results demonstrated that the calibration curves for both analytes have good linearity (r≥0.995) over a concentration range of 5.00-3000ng/mL. The assay was validated according to the regulatory bioanalytical guidelines and proved acceptable.