Determination of pinocembrin in human plasma by solid-phase extraction and LC/MS/MS: application to pharmacokinetic studies

A sensitive, fast and specific method for the quantitation of pinocembrin in human plasma based on high-performance liquid chromatography-tandem mass spectrometry (LC/MS/MS) was developed and validated. Clonazepam was used as the internal standard (IS). After solid-phase extraction of 500L plasma, pinocembrin and the IS were separated on a Luna C-8 column using the mobile phase composed of acetonitrile-0.3mm ammonium acetate solution (65:35, v/v) at a flow rate of 0.25mL/min in isocratic mode. The detection was performed on a triple quadrupole tandem mass spectrometer by multiple reaction monitoring via an electrospray ionization source in negative mode by AB SCIEX Qtrap 5500. The assay was linear from 1 to 400ng/mL, with within- and between-run accuracy (relative error) from -1.82 to 0.54%, and within- and between-run precision (CV) below 5.25%. The recovery was above 88% for the analyte at 1, 50 and 300ng/mL. This analytical method was successful for the determination of pinocembrin in human plasma and applied to a pharmacokinetic study of pinocembrin injection in healthy volunteers after intravenous drip administration. Copyright (c) 2014 John Wiley & Sons, Ltd.