[Quantitative determination of chlorogenic acid in eucommia leaf by high performance liquid chromatography]

An HPLC method for the quantitative determination of chlorogenic acid in Eucommia leaf was investigated. The sample was extracted with methanol solution containing 5% fomic acid and then analyzed by HPLC. The operating conditions were Shim-pack CLC-ODS column (6.0 mm i.d. x 150 mm, 5 microns) at 40 degrees C, mobile phase of methanol-0.01 mol/L KH2PO4(25:75, V/V; pH 3.9) at 1 mL/min and UV detection at 328 nm. Mercaptopurine was selected as the internal standard. There was a good linear relationship between the response (area ratio of chlorogenic acid to mercaptopurine) and the concentration of sample in the range of 25-300 mg/L for chlorogenic acid. The corresponding regression equation was Y = 8.0368X + 0.001275, r = 0.9999. The average recovery was 99.89% and RSD was 1.45%(n = 6). The results showed that this method is simple, specific and accurate.