An improvement of separation and response applying post-column compensation and one-step acetone protein precipitation for the determination of coenzyme Q10 in rat plasma by SFC-MS/MS.

Coenzyme Q10 (CoQ10) solid dispersion was prepared to improve its oral bioavailability due to the poor solubility of CoQ10. To evaluate the pharmacokinetic behaviors of CoQ10 solid dispersion, a simple, rapid, sensitive and environment friendly method for the determination of CoQ10 in rat plasma was developed. In this study, samples were prepared by one-step protein precipitation with acetone and then the supercritical fluid chromatography-electrospray ionization tandem mass spectrometry (SFC-ESI-MS/MS) method was used. The separation was achieved by an ACQUITY UPC(2)™ BEH 2-EP column (100mm×3mm, 1.7μm) maintained at 35°C, using carbon dioxide (≥99.99%) and methanol (85:15, v/v) as the mobile phase at a flow rate of 1.0ml/min. To improve the response and sensitivity, the compensation solvent of methanol with 2mM ammonium acetate at a flow rate of 0.2ml/min was used and the total analysis time was only 1.5min for each sample. The detection was carried out on a tandem mass spectrometer with electrospray ionization (ESI) source and the mass transition ion pair was m/z 881.0→197.0 and 285.1→193.0 for CoQ10 and diazepam, internal standard (IS), respectively. Calibration curve was linear over the concentration range of 2.00-500.00ng/ml (r(2)≥0.998) with a lower limit of quantification of 2.00ng/ml. The intra- and inter-day accuracy and precision were below 15% for all quality control samples. The proposed method was rapid, accurate and reproducible, which was suitable to compare the pharmacokinetic behaviors in rats after a single oral dose of 100mg/kg CoQ10 solid dispersion or tablets.