银杏酸的高效液相色谱法测定

目的建立银杏酸的简便预净化处理和HPLC含量测定方法。方法用LC/DAD/ESI/MS对银杏酸进行定性鉴定。银杏叶经正己烷提取、硅胶柱色谱净化处理,HPLC测定。色谱分析条件:色谱柱为Inertsil ODS-2,流动相为甲醇-3% HAc溶液(92∶8),流速1.0 mL·min^-1,柱温40℃,紫外检测波长310 nm。结果银杏叶中存在5种银杏酸C13∶0,C15∶0,C15∶1,C17∶1和C17∶2,其中C15∶1和C17∶1约占银杏酸的85%,C17∶2银杏酸未见国内文献报道。银杏叶提取物经硅胶柱色谱处理后,其HPLC谱中除银杏酸峰外,几无其他杂质峰。平均回收率97.0%,RSD为1.7%(N=6)。结论该方法准确、简便、可靠,可用于银杏酸的定量分析。

DETERMINATION OF GINKGOLIC ACIDS BY HIGH PERFORMANCE LIQUID CHROMATOGRAPHY

AIM: To establish a simple pre-treated method and high performance liquid chromatographic method for separation and determination of ginkgolic acids in Ginkgo biloba leaves. METHODS: The ginkgolic acids in the German standard sample were identified by LC/DAD/ESI/MS. The methods for pre-treatment and high performance liquid chromatography determination of ginkgolic acids were studied. Ginkgo biloba leaves were extracted with n-hexane in Soxhlet apparatus, then concentrated under vacuum. The ginkgolic acids can be determined directly by HPLC after one-pre-purified-step by silica gel column chromatography. The eluant was petroleum ether-diethyl ether-formic acid (89:11:1). The chromatographic column was Inertsil ODS-2; the mobile phase was methanol-3% acetic acid (92:8); the flow rate was 1.0 mL.min-1; the column temperature was 40 degrees C; the detection wavelength was at 310 nm. RESULTS: There were five kinds of ginkgolic acid (C13:0, C15:1, C17:2, C15:0 and C17:1) in ginkgo biloba leaves. The relative percentage content of ginkgolic acids C15:1 and C17:1 was about 85%. Ginkgolic acid C17:2 had not been reported in China. The HPLC indicates that there was nearly no impurities except ginkgolic acids after treated by column chromatography. The results showed that the content of ginkgolic acids in the leaves of Ginkgo biloba collected in April, May and June was 1.48%, 1.19% and 1.11% respectively. The average recovery of Ginkgo biloba leaves collected in June was 97.0%, RSD was 1.7% (n = 6). CONCLUSION: The method is accurate, simple and reliable, and can be used for determination of ginkgolic acids in Ginkgo biloba leaves.