Simultaneous determination of five constituents in Qinpijiegu capsule by high-performance liquid chromatography coupled with tandem mass spectrometry.

A rapid high-performance liquid chromatography coupled with tandem mass spectrometry method was developed for the simultaneous determination of five constituents in Qinpijiegu capsule (QJC), a classical Tibetan prescription. The separation of five compounds such as aesculin, aesculetin, fraxin, peimine and peimininewas performed on a Purospher STAR LP RP-C-18 (250 x 4.6 mm, 5 mu m) column with linear gradient elution of acetonitrile-0.3 parts per thousand formic acid water in 13 min. Detection was carried out by multiple reaction monitoring mode using electrospray ionization in the positive and negative ion switching mode. The sample was prepared with ultrasound extraction with methanol, which could obtain higher extraction efficiency and shorter extraction time comparing to reflux extraction with alkalized chloroform-methanol. The proposed method was applied to analyze three batches of samples with acceptable linearity (r(2) > 0.9977), precision [ relative standard deviation (RSD) < 7.40%], repeatability (RSD < 2.49%), stability [ relative error (RE) < 9.15%] and recovery (RSD < 10.76%). This is the first development of a multicomponent quantitation method for the quality control of QJC. Furthermore, the new established method was proven to be highly sensitive and effective in evaluating the quality of QJC.