Determination of 11 Phosphodiesterase Inhibitors in Health Food by LC-Quadrupole-Orbitrap High Resolution MS

The health food sample was extracted ultrasonically for 15 min with 50% (φ) methanol solution, and then the extract was diluted to 50.0 mL with water. After centrifugation, the supernatant was taken and filtered with 0.22 μm millipore filter. LC-quadrupole-orbitrap high resolution MS was applied to the determination of 11 phosphodiesterase inhibitors in the filtrate. Waters HSS T3 chromatographic column was used as stationary phase, and the mixture of 0.1% (φ) formic acid solution and acetonitrile mixed in different ratios was used as mobile phase in gradient elution. ESI⁺ and the full scanning mode were adopted in MS. Linear relationships between values of peak area and mass concentration of the 11 phosphodiesterase inhibitors were kept in the same range of 2-100 μg·L^-1, with lower limits of determination (10S/N) in the range of 0.02-0.5 μg·L^-1. On the base of blank sample, test for recovery was made by standard addition method; values of recovery found were in the range of 75.7%-98.9%, with RSDs (n=6) of determined values in the range of 5.9%-14%.