苎麻籽总黄酮含量测定方法比较研究

Comparative study on determination method of total flavonoids content in ramie seeds

中文关键词:  苎麻籽  总黄酮  分光光度法

英文关键词:ramie seeds  total flavonoids  spectrophotometry

中文摘要:

      目的 比较苎麻籽总黄酮含量的测定方法。方法 以芦丁和槲皮素为对照品, 比较直接测定法、NaNO2-Al3+-NaOH法、AlCl3法3种比色方法下苎麻籽(70%乙醇提取液)的紫外-可见光谱图, 并通过精密度、稳定性、干扰试验、加标回收率试验对所选方法进行评价。结果 芦丁和槲皮素均不适合作为直接测定苎麻籽总黄酮的对照品; NaNO2-Al3+-NaOH法最大吸收波长为500 nm, 但受某些非黄酮类物质干扰, 使得该方法下的总黄酮含量测定值虚高; AlCl3法以芦丁为对照品, 测定波长为401 nm, 在0.004~0.02 mg/mL范围内浓度与吸光度值成良好的线性关系, 相关系数r2=0.9998, 该法受干扰小, 精密度高, 平均回收率为(99.46±4.16)%, 显色后在20~60 min内吸光值稳定。结论 AlCl3法简单可行, 适用于苎麻籽提取物中总黄酮含量的测定。

英文摘要:

      Objective To compare the determination methods of total flavonoids in ramie seeds. Methods The ultraviolet-visible spectra of 2 standard reference substance (rutin and quercetin) and total flavonoids (solvent: 70% ethanol) in ramie seeds based on the direct colorimetry, NaNO2-Al3+-NaOH method and AlCl3 method were compared, and the selected method was evaluated by precision, stability, interference test, and recovery test. Results Both rutin and quercetin were not suitable as a standard reference substance for the direct determination of total flavonoids in ramie seeds. The maximum absorption wavelength was 500 nm for total flavonoids by NaNO2-Al3+-NaOH method. However the total flavonoid content measured was higher using NaNO2-Al3+-NaOH method due to interference with certain non-flavonoids. For the AlCl3 method, the measurement wavelength was 401 nm using rutin as a reference substance, and this method had a good linear relationship in the concentration range of 0.004?0.02 mg/mL (r2=0.9998). The AlCl3 method had the advantages of low interference and high precision. The average recovery rate was (99.46±4.16)%. The absorbance was stable within 20?60 min after color development. Conclusion The AlCl3 method is simple, feasible, and is suitable for the determination of total flavonoids in ramie seeds extract.