Simultaneous determination of the 10 major components of Da-Cheng-Qi decoction in dog plasma by liquid chromatography tandem mass spectrometry

A liquid chromatography tandem mass spectrometry (LC–MS/MS) method was developed for the simultaneous determination of the 10 major components of Da-Cheng-Qi decoction (rhein, emodin, aloe-emodin, chrysophanol, rheochrysidin, naringin, naringenin, hesperidin, magnolol and honokiol) in dog plasma. Plasma samples were spiked with internal standard (ibuprofen), acidified with HCl and extracted twice by liquid–liquid extraction using ethyl acetate. Separation was performed on a YMC-Pack ODS-A C18 column (5 μm, 150 mm × 4.6 mm) and a C18 guard column (5 μm, 4.0 mm × 2.0 mm) with methanol–water (92:8, v/v) at a flow rate of 0.3 mL/min. The LC/MS system was operated under the multiple reaction monitoring mode using electrospray ionization in the negative ion mode. All analytes showed good linearity over a wide concentration range (r > 0.99). The linear range of the calibration curves was 5000–19.53 ng/mL for rhein; 400–3.13 ng/mL for emodin; 800–3.13 ng/mL for aloe-emodin, chrysophanol, naringin, naringenin, hesperidin, magnolol and honokiol; 160–0.63 ng/mL for rheochrysidin. The lower limit of quantification was: 19.53 ng/mL for rhein; 3.13 ng/mL for emodin, aloe-emodin, chrysophanol, naringin, naringenin, hesperidin, magnolol and honokiol; 0.63 ng/mL for rheochrysidin. The overall mean accuracy for the 10 major components of Da-Cheng-Qi decoction was 90.40–108.60%. Intra-day and inter-day precision was ≤12.43% and ≤11.32%, respectively. We conclude that this method is appropriate for simultaneous determination of the 10 major components of Da-Cheng-Qi decoction in dog plasma and the investigation of the pharmacokinetics of Da-Cheng-Qi decoction in dog.