HPLC analysis of the organic acids

Nine organic acids in the bayberry juices were analysed using an Agilent 1260 HPLC system (Agilent, CA, USA) equipped with an ultra-violet detector. The detection wavelength was set at 210 nm. The organic acids were separated by an Agilent C₁₈ column (250 mm × 4.5 mm × 5 μm) at 30 °C. The mobile phase was 0.1 mol/L KH₂PO₄–H₃PO₄ solution. The flow speed was set to 0.7 mL/min. The identification and the concentrations of the organic acids were determined by the external standards method. The average recoveries for the nine organic acids ranged from 76.38 to 103.04%. The relative standard deviation (RSD) of the standards ranged from 0.08 to 10.89%.