Simultaneous determination of 1,3-dicaffeoylquinic acid and caffeic acid in rat plasma by liquid chromatography/tandem mass spectrometry and its application to a pharmacokinetic study

Abstract

A rapid and highly sensitive liquid chromatography/tandem mass spectrometry method for simultaneous determination of 1,3-dicaffeoylquinic acid and caffeic acid in rat plasma was developed. The analytes and internal standard (IS), tinidazole, were extracted from rat plasma via liquid/liquid extraction with ethyl acetate and separated on an Agilent Zorbax SB C18 column within 4 min. Quantitation was performed on a triple quadrupole mass spectrometer employing an electrospray ionization technique, operating in a multiple reaction monitoring (MRM) and negative ion mode. The precursor to product ion transitions monitored for 1,3-dicaffeoylquinic acid, caffeic acid and IS were m/z 515.2 → 353.0, 178.9 → 134.9, and 246.0 → 125.8, respectively. The assay was validated in the linear range of 4.00–96.0 ng mL⁻¹ for 1,3-dicaffeoylquinic acid and 2.00–128 ng mL⁻¹ for caffeic acid. The intra- and inter-day precisions (RSD%) were within 8.89% for each analyte. The absolution recoveries were greater than 73.52% for 1,3-dicaffeoylquinic acid and 74.32% for caffeic acid. Each analyte was proved to be stable during all sample storage, preparation and analytical procedures. The method was successfully applied to a pharmacokinetic study of Dengzhanxixin injection in 8 rats.