离子液体辅助超声萃取-高效液相色谱同时测定半边莲中6 种黄酮类化合物

目的：通过单因素试验和正交试验对离子液体辅助萃取半边莲中黄酮类化合物的条件进行优化，建立高效液相色谱法同时分离测定半边莲中芦丁、槲皮素、柚皮素、橙皮素、山柰酚和芹菜素的方法。方法：采用InertSustain C18色谱柱（150 mm×4.6 mm，5 μm）进行分离；流动相为甲醇（B）-乙酸溶液（A，pH 3.0），梯度洗脱；流速1.0 mL/min；紫外检测波长285 nm；柱温35 ℃。结果：以黄酮类化合物的提取量为指标，最佳提取条件为甲醇体积分数80%、固液比1∶80（g/mL）、萃取时间30 min、离子液体浓度0.6 mol/L。在优化的色谱条件下，芦丁、槲皮素、柚皮素、橙皮素、山柰酚和芹菜素分离效果良好；定性检出限（RSN = 3）依次为0.001 2、0.002 3、0.002 6、0.000 2、0.001 0、0.000 6 μg/mL；样品回收率为91.77%～102.53%。结论：该萃取方法操作简单快速，为半边莲中黄酮类化合物的提取分离及检测提供了有效的方法。

Simultaneous Determination of 6 Flavonoid Compounds in Herba Lobelia chinensis by High Performance Liquid Chromatography after Ionic Liquid Assisted Ultrasonic Extraction

Objectives: To optimize the conditions for ionic liquid-assisted extraction of flavonoids compounds from Herba
Lobelia chinensis using single factor and orthogonal array designs and consequently to establish a high performance liquid
chromatography (HPLC) method for simultaneous determination of rutin, quercetin, naringgenin, hesperetin, kaempferol and
apigenin in Herba Lobelia chinensis. Methods: The 6 compounds were separated on an InertSustain C18 (150 mm × 4.6 mm, 5 μm)
using a mobile phase consisting of methanol and acetic acid (pH 3.0) with gradient elution at a flow rate of 1.0 mL/min.
The detection wavelength was set at 285 nm. The column temperature was maintained at 35 ℃. Results: The optimum
extraction conditions for total flavonoids were determined as follows: 80% (V/V) aqueous methanol as extraction solvent;
solid-to-liquid ratio, 1:80 (g/mL); extraction time, 30 min; and ionic liquid concentration, 0.6 mol//L. Under these conditions,
rutin, quercetin, naringgenin, hesperetin, kaempferol and apigenin were separated satisfactorily. The limits of detection (LODs)
for these flavonoid compounds were 0.001 2, 0.002 3, 0.002 6, 0.000 2, 0.001 0 and 0.000 6 μg/mL, respectively. The recoveries
of spiked samples ranged from 91.77% to 102.53%. Conclusion: The proposed method is simple and rapid, and it can provide an
efficient means for the extraction, separation and determination of flavonoid compounds in Herba Lobelia chinensis.