固相萃取-紫外分光光度法快速测定黄花蒿中青蒿素含量

目的: 建立固相萃取(SPE)净化后紫外分光光度法(UV)快速测定黄花蒿中青蒿素含量。方法: 黄花蒿干叶粉末中的青蒿素用无水乙醇超声波提取(200 W,40 kHz),最佳提取条件为料液比1:20(g:mL),超声波萃时间15 min,温度25 ℃。提取液0.05 mol · L^-1 氢氧化钠水溶液45 ℃衍生20 min。衍生化后经C₁₈ SPE柱净化,乙醇-0.01 mol · L^-1 磷酸盐缓冲液(pH 5.8)(15:85)洗涤杂质,乙醇-0.01 mol · L^-1 磷酸盐缓冲液(pH5.8)(33:67)洗脱青蒿素衍生物Q₂₅₉。洗脱液用紫外分光光度计259 nm波长处测定。结果: 经高效液相色谱(HPLC)检测,SPE净化后Q₂₅₉ 回收率在98.0%~105.9%;Q₂₅₉ 对λ₂₅₉ 光吸收贡献从26.8%~53.5%提高到92.0%~100%,λ₂₅₉ 有光吸收的杂质基本除去;SPE-UV法与HPLC法相对误差小于10%。结论: SPE-UV法经方法学验证,可作为黄花蒿种植、收购时大量、快速检测黄花蒿中青蒿素含量的检测方法。

Objective: To establish a method for rapid determination of artemisinin in Artemisia annua L.using solid phase extraction (SPE) followed by UV-spectrophotometry. Methods: Artemisinin was extracted from A.annua using anhydrous ethanol as the extracting solvent by ultrasonic wave(200 W, 40 kHz).The optimal extraction condition was as follows:the solid-liquid ratio 1:20(g:mL), the extraction time 15 minutes at 25 ℃.The extraction solution was derivatized in 0.05 mol · L^-1 NaOH solution for 20 min at 45 ℃.The sample was purified by C₁₈ SPE column with ethanol-0.01 mol · L^-1 phosphate buffer (pH5.8)(15:85), eluted by ethanol-0.01 mol · L^-1 phosphate buffer (pH 5.8)(33:67)and detected by UV-pectrophotometry at 259 nm. Results: The recovery rate of Q₂₅₉ was between 98.0% and 105.9% after purifying by SPE which was detected by HPLC.And the contribution of Q₂₅₉ for light absorption in λ₂₅₉ improved from 26.8%-53.5% to 92.0%-100%, which indicated that the impurities absorbed in λ₂₅₉ were almost removed.The relative error between SPE-UV and HPLC was less than 10%. Conclusion: The SPE-UV after verification methodology could work effectively in on-site rapid determination of arteannuin content in large quantity of A.annua during planting and purchasing.