Determination of fenofibric acid in human plasma by ultra performance liquid chromatography-electrospray ionization mass spectrometry: application to a bioequivalence study

A rapid, specific and sensitive ultra‐performance liquid chromatography tandem mass spectrometry method was developed for the determination of fenofibric acid in human plasma. The method involves simple, one‐step liquid–liquid extraction procedure coupled with an Acquity UPLCTM BEH C18 column (50 × 2.1 mm, i.d., 1.7 µm) with isocratic elution at a flow‐rate of 0.2 mL/min and mefenamic acid was used as the internal standard. The Quattro Premier XE mass spectrometry was operated under the multiple reaction‐monitoring mode using the electrospray ionization technique. Using 250 µL plasma, the methods were validated over the concentration rang 0.05–7.129 µg/mL, with a lower limit of quantification of 0.05 µg/mL. The intra‐ and inter‐day precision and accuracy were within 9.3%. The recovery was 66.7% and 52.6% for fenofibric acid, and mefenamic acid, respectively. Total run time was 1.8 min only for each sample, which makes it possible to analyze more than 350 samples per day. Copyright © 2009 John Wiley & Sons, Ltd.