采用反相高效液相色谱法测定银杏中5种银杏酸的含量。样品用甲醇为提取溶剂回流提取后定容至25 mL,取2 mL用正己烷从含有硅藻土的pH 2~3溶液进行液-液萃取,上清液真空旋干,加甲醇定容至2 mL后,取20 μL进样用Waters Symmetry-C18色谱柱分离,以甲醇-水(88+12,含5%乙酸)为流动相,二极管阵列检测器在波长310 nm处检测。峰面积与5种银杏酸的质量浓度分别在一定范围内呈线性关系,方法的检出限(3S/N)在0.26~1.37 mg·L-1之间。方法的平均回收率为99.2%,测定值的相对标准偏差(n=5)为6.83%。

Five ginkgolic acids in ginkgo biloba L. were extracted from the sample with methanol under refluxing. The extract was made up to 25 mL and an aliquot of 2 mL was taken and purified by extraction with n-hexane from a solution containing diatomite at pH 2-3. The supernatant was taken and evaporated to dryness rotationally under vacuum. The residue was dissolved with 2 mL of methanol, and 20 μL of the solution were introduced for RP-HPLC analysis by separation on Waters Symmetry-C18 column with the mobile phase of CH3OH-H2O (88+12, containing φ 5% of HOAc). Contents of the 5 acids were determined by DAD at the wavelength of 310 nm. Linear relationships between values of peak area and mass concentration of 5 ginkgolic acids were kept in the definite range, with detection limit (3S/N) in the range of 0.26-1.37 mg·L-1. The value of average recovery found by standard addition method was 99.2%, with value of RSD (n=5) of 6.83%.