Simultaneous Determination of 8 Chemical Components in Sargentodoxa Cuneata by UHPLC Combined with Electrochemical Detector

A method for the simultaneous determination of hydroxytyrosol, protocatechuic acid, salidroside, tyrosol, catechin, cryptochlorogenic acid, chlorogenic acid and epicatechin in Sargentodoxa cuneata by ultra-high performance liquid chromatography (UHPLC) combined with electrochemical detector (ECD) was proposed. The Sargentodoxa cuneata sample powder about 1 g was passed through 0.42 mm sieve, and extracted ultrasonically with 30 mL of 30% (φ) methanol solution for 10 min. After centrifugation, the extract was filtered through 0.22 μm membrane for analysis. Waters ACQUITY UPLC^® BEH Shield RP18 column was used as the stationary phase, and a mixture of acetonitrile and 50 mmol·L^-1 potassium citrate buffer (pH 2.76) at different volume ratios was used as the mobile phase for gradient elution. The detection potential of Coulomb detection pool of ECD was 350 mV in the first channel for hydroxytyrosol, protocatechuic acid, catechin, cryptochlorogenic acid, chlorogenic acid and epicatechin, and 600 mV in the second channel for salidroside and tyrosol. As shown by the results, linear relationships between values of mass concentration and peak area of 8 chemical components were kept in the definite ranges, with detection limits (3S/N) in the range of 0.7-8.5 μg·L^-1. Tests for precision (n=6) and stability (n=7) were carried out on the mixed standard solution or sample solution, and RSDs of the peak areas of target compounds were less than 5.0%. Test for recovery was made on the actual sample, giving results in the range of 96.0%-102%. This method was applied to analysis for the 24 batches of Sargentodoxa cuneata samples from different origins, salidroside and chlorogenic acid in S15 and S18 samples did not meet the requirements.