分散液液微萃取-高效液相色谱法同时测定大枣中白桦脂酸、齐墩果酸及熊果酸

Dispersive Liquid-liquid Microextraction Combined with High Performance Liquid Chromatography to Determine Betulinic Acid,Oleanoic Acid and Ursolic Acid in Jujube

建立了分散液液微萃取,结合高效液相色谱法(DLLME-HPLC)同时对大枣中的白桦脂酸(BA)、齐墩果酸(OA)及熊果酸(UA)含量进行测定。样品经甲醇超声提取,离心后取上清液旋蒸至近干,用甲醇复溶残渣并定容。取1mL溶液,加入1mL氯仿与3mL水,涡旋2min混匀进行DLLME。取氯仿层,氮吹至干,甲醇复溶后进样分析。BA在20.2~303μg·mL-1范围内线性良好(r=0.999),平均回收率为98.3%;OA在10.1~152μg·mL-1范围内线性良好(r=0.993),平均回收率为97.5%;UA在10.1~152μg·mL-1范围内线性良好(r=0.999),平均回收率为97.8%;相对标准偏差(RSD)<2.0%。本方法能够对大枣中BA、OA和UA进行准确的含量测定。

We establish a simple and effective method by combining dispersive liquid-liquid microextraction with high performance liquid chromatography(HPLC)for simultaneously determination of betulinic acid,oleanolic acid and ursolic acid in jujube.The jujube sample was ultrasonically extracted by methanol.After centrifugation,the supernatant was evaporated to dryness,and the residue was reconstituted with methanol.Then 1 mL of the solution was teken out,and 1 mL chloroform and 3 mL water was added.The mixed liquor was vortexed for 2 minutes for dispersive liquid-liquid microextraction.Then the chloroform layer was dried by nitrogen and reconstituted by methanol for HPLC analysis.The liner ranges of betulinic acid and oleanoic acid and ursolic acid were 20.2-303μg·mL-1(r=0.993),and 10.1-152μg·mL-1(r=0.999)and 10.1-152μg·mL-1(r=0.999)and the average recoveries were 98.3%,97.5%and 97.8%,respectively,with RSD<2.0%.