Determination of dihydroquercetin in cocoa products by high performance liquid chromatography

ObjectiveIn the experiment，using liquid-liquid extraction solid-phase extraction method to remove fat content and interfering impurities from cocoa products，establishing a high performance liquid chromatography method for detecting the content of dihydroquercetin.MethodsAfter the sample was extracted with methanol-2% acetic acid water （V∶V=1∶1），the fat content in the solution was first removed by liquid-liquid extraction purification，then it was secondary purified by hydrophilic and lipophilic solid-phase extraction column.The mobile phase was 0.1% acetic acid water-methanol，and it was separated by C18 reversed-phase chromatographic column.Finally，it was analyzed by high performance liquid chromatography with diode array detector.ResultsThe dihydroquercetin showed a good linear relationship in the range of 0.1-100 μg/mL，the linear correlation coefficient was 0.999 9，the detection limit was 1 mg/kg，the quantitative limit was 3 mg/kg，the average recovery rate was 101.7%-106.7%，and the RSD was 0.35%-1.60% （n=6）.ConclusionThe method can remove fat soluble impurities in cocoa products，with high sensitivity and accuracy，and is suitable for accurate determination of dihydroquercetin content in high-fat foods.