Rapid and sensitive HPLC-MS/MS method for quantitative determination of isochlorogenic acid B in rat plasma and its application in pharmacokinetic study.

A sensitive LC-ESI-MS/MS method for determination of isochlorogenic acid B in rat plasma was developed and validated in the present study. Plasma samples were prepared by a simple protein precipitation with methanol containing resveratrol as internal standard (IS). The chromatographic separation was performed on a Zorbax SB-C18 column (3.5 μm, 2.1 mm×100 mm, Agilent, USA) at a flow rate of 0.2 mL/min using methanol/water containing 0.1% formic acid (v/v) as mobile phase. The detection was performed on a triple quadrupole tandem mass spectrometer equipped with Electronic Spray Ion by selected reaction monitoring (SRM) of the transitions at m/z 515.3→352.9 for isochlorogenic acid B and m/z 227.1→143.1 for IS, respectively. The calibration curve of the method was linear over the range of 5-2500 ng/mL (r2 = 0.9982). The intra- and inter-day precisions (R.S.D.%) were less than 12.46%, and the accuracy (R.E.%) was within ±5.80%. Isochlorogenic acid B was sufficiently stable under all relevant analytical conditions. The validated method was successfully applied to the plasma pharmacokinetic studies of isochlorogenic acid B in rats. It was found that isochlorogenic acid B had non-linear pharmacokinetic characteristics in rats within the dosage ranges from 5 to 20 mg/kg. [ABSTRACT FROM AUTHOR]