分光光度测定总黄酮法的适用性

Suitability of Spectrophotometry for Determination of Total Flavonoids Spectrophotometry

为建立测定天南星总黄酮含量的方法,通过比较黄酮及苷、黄酮醇及3位苷共12个化合物的NaNO2-Al(NO3)3-NaOH法和AlCl3-KAc法的紫外和可见光谱,分析了分光光度测定总黄酮法的适用性。结果显示,与相应方法的有关原理相矛盾,尤其是芹菜素及苷在两方法中均未有相应现象产生。为此,进行了新方法研究,比较了各黄酮在三乙胺介质中的紫外可见光谱,结果显示,黄酮及苷和3-黄酮醇苷最大吸收均红移;将三乙胺法应用于天南星,方法验证结果符合含量测定要求,对照品夏佛托苷在1.54～21.5mg/L范围内与吸光度有良好线性关系(r=0.9997),平均回收率为99.3%(RSD=1.1%,n=9)。方法重现性好,可操作性强。适用性研究表明,3种方法均只适用于部分黄酮类成分分析。

To develop a method for determining the total flavonoids in Rhizoma Arisaematis, the suitability of NaNO2-Al（NO3）3-NaOH and AlCl3-KAc ultraviolet-visible （UV-Vis） spectrophotometric methods were studied by comparing the spectra of 12 compounds, containing flavonoids and their glycosides, flavonols and 3-flavonol glycosides. The results showed that the expected phenomenon of the apigenin and its glycosides did not appear. In the medium of triethylamine, theses compounds could produce a red shift of the maximum absorption. This phenomenon could be applied for determining the total flavonoids in Rhizoma Arisaemati. The method was verified to satisfy the requirements of quantitative analysis. There was a good linear relationship between the concentrations and the absorbance of schaftoside （the reference standard） in the ranges of 1.54-21.5 mg/L（r=0.9997）, and the average recovery was 99.3% （RSD=1.13%, n=9）. The method, which is convenient and reproducible, can be used to control the quality of flavonoids.