11种凤凰单丛茶中9种黄酮酚类物质的检测方法建立与分析

建立了高效液相色谱法(HPLC)同时测定凤凰单丛茶中9种黄酮酚类物质的检测方法。采用色谱柱Waters Xterra■MS C18(4.6 mm×250 mm,5μm),以乙腈和0.02%乙酸为流动相进行梯度洗脱,流速1.0 mL/min,柱温25℃,二极管阵列检测器280 nm波长检测,外标法定量。结果表明,9种黄酮酚类物质中香豆酸、绿原酸、儿茶素、芦丁和槲皮素在0.01~0.20 mg/mL,木犀草素、金丝桃苷、山奈酚和槲皮苷在0.025~0.250 mg/mL线性关系良好,相关系数(r)均大于0.999;方法检出限为0.2~1.8μg/g,定量下限为0.6~5.9μg/g。在25μg/g和250μg/g两个加标水平下,9种黄酮酚类物质的平均回收率为95.4%~104.8%,相对标准偏差RSD(n=6)均小于5%。该方法操作简便、快速、准确,适合于黄酮酚类物质的定性与定量检测。

Influence of Solvent Polarity and Conditions on Extraction of Antioxidant, Flavonoids and Phenolic Content from A verrhoa bilimbi

This paper presents the influence of solvent polarity and extraction conditions on the extraction of total flavonoid, total phenolic and antioxidants from Averrhoa bilimbi. The experiment was performed using a different solvent at different extraction conditions, including extraction time （15-240 min）, temperature （30-70 ℃） and agitation speed （50-300 rpm）. Results showed that yields of extraction varies with solvent polarity. Extraction using 50% aqueous methanol gives the highest antioxidant activity and flavonoid content. The highest total flavonoid content （193.3 μg quercetin equivalent/g dry weight）, total phenolic content （717.8 μg gallic acid equivalent/g dry weight） and antioxidant activity （77%） was achieved using 50% methanol, at 70 ℃ and agitation speed of 300 rpm. This work may be useful for obtaining higher bioactive compounds during the extraction process of A. bilimbi.