[Determination of 28 exogenous medicines and endogenous components in herbal drink using high performance liquid...

A high performance liquid chromatographic method for the determination of 28 exogenous medicines and endogenous components in the herbal drink was developed. The samples were extracted ultrasonically with methanol-water (70:30, v/v), and the extracts were separated in a Thermo Accucore C18 column (100 mm×4.6 mm, 2.6 μm) with methanol-acetonitrile-20 mmol/L ammonium acetate solution (pH 4.2) as the mobile phases by gradient elution. The flow rate was 1.2 mL/min and the column temperature was 35℃. The detection wavelengths were 254 nm and 220 nm. Quantification analysis was performed by the external standard method. The result showed the compounds had a good linear relationship in the range of 1-100 mg/L, and the correlation coefficients (r) were not less than 0.999. The limits of detection (LODs) of the 28 compounds were 1-10 mg/kg in the liquid sample and 20-200 mg/kg in the solid sample. The average recoveries of the 28 compounds in the liquid and solid samples were in the ranges of 88.8%-118.6% and 92.7%-112.3% with the relative standard deviations (RSDs) of 0.1%-6.7% and 0.1%-6.4%, respectively. The method was applied to analyze 456 herbal drink samples, and 55 positive samples were found. The positive rate was 12.1%. The developed method was simple and reliable, and it was suitable for the determination of 28 components in the herbal drink.