Laurent S
Arch Int Physiol Biochim. 1975 Oct;83(4):735-52. doi: 10.3109/13813457509081892.
Various processes of extraction and quantitative analysis of a condensed tannin in a plant extract, which also includes some chlorogenic acids, have been examined. 60% methanol, at 50 degrees C, proved the most efficient extraction solvent. Several methods of analysis have been tried. The measure of the colour intensity obtained by the action of sulphuric vanilline on flavanols cannot be used because it depends on the tannin condensation stage. It is impossible to separate tannin from chlorogenic acids using the methods of adsorption by skin or nylon powders, or precipitation by polyvinylpyrrolidone. Only paper chromatography, followed by the distinct elution of the various phenolic compounds, allows the tannin evaluation by subtraction; but owing to the variability of the results, many more experiments are necessary. Some other processes are being studied.
已对植物提取物中缩合单宁（其中还包括一些绿原酸）的各种提取和定量分析方法进行了研究。结果表明，50℃的60%甲醇是最有效的提取溶剂。尝试了几种分析方法。硫酸香草醛作用于黄烷醇所获得的颜色强度测量方法不可用，因为它取决于单宁的缩合阶段。使用皮肤或尼龙粉末吸附法或聚乙烯吡咯烷酮沉淀法无法将单宁与绿原酸分离。只有纸色谱法，随后对各种酚类化合物进行单独洗脱，才能通过减法对单宁进行评估；但由于结果的变异性，还需要进行更多实验。正在研究其他一些方法。
