HPLC法测定宁夏红葱中槲皮素与山奈酚的含量

HPLC Determination of Quercetin and Kaempferol in Allium cepa var.Proliferum from Ningxia

以宁夏同心红葱、盐池红葱以及市售白葱为材料,采用甲醇+超声波提取法对样品中的槲皮素与山奈酚进行了提取,并根据正交试验设计确定最佳提取条件。用高效液相色谱法,以保留时间定性、外标法定量,研究葱样中槲皮素和山奈酚的含量,对色谱条件进行优化,并比较分析了两个地区红葱与市售白葱中的槲皮素和山奈酚含量差异。结果表明,方差分析可知槲皮素与山奈酚的最佳提取条件为:超声温度为60℃、时间为50 min、甲醇浓度为75%;最佳色谱条件为:色谱柱XDB-C18(250 mm×4.6 mm,5μm),柱温为30℃,流动相为甲醇0.5%冰醋酸(30∶70),流速1.0 m L/min,检测波长为290 nm。通过比较分析可知,红葱中槲皮素与山奈酚含量均明显高于市售白葱,而盐池红葱中槲皮素与山奈酚含量也均明显高于同心红葱。

The determination method and extracting conditions of flavonoids in two types of red onions from Ningxia were mainly investigated, and compared with those of Chinese onions in our study. Taking Tongxin red onions, Yanchi red onions and Chinese onions as the research objects, extract of quercetin and kaempferol were extracted with methanol ＋ultrasonic extraction methods from three different samples, and the extraction conditions was optimized by the orthogonal experimental design methods. Then the contents of quercetin and kaempferol in three different samples were determined by high-pressure liquid chromatography（HPLC）, and the determination conditions were optimized. The results showed that the optimum extraction conditions were：ultrasonic temperature 60 ℃, ultrasonic time 50 min, methanol concentration 75 %. The optimal determination conditions were Agilent XDB-C18column（250 mm ×4.6 mm, 5 μm）, the column temperature was 30 ℃,mobile phase was methanol：0.5 % acetic acid=30 ∶ 70, the flow rate was 1.0 mL/min, the detection wavelength was 290 nm. As the comparative analysis, the contents of quercetin and kaempferol in two red onions were significantly higher than those of Chinese onions, and the contents of quercetin and kaempferol in Yanchi red onions were obviously higher than those of Tongxin red onions.