紫外法和皮粉法测定塔拉单宁含量的对比研究

分别采用紫外法和皮粉法对5种不同含量的塔拉单宁进行对比研究，并利用SPSS软件对单宁含量测定结果进行显著性检验，结果表明：高纯度塔拉单宁(93%)分别用紫外法和皮粉法测定单宁含量时实验结果并未显著差异(P>0.05),而4种纯度为60%左右塔拉单宁的实验结果均具有显著性差异(P<0.05),皮粉法测得的单宁含量均比用紫外法测得的结果高，差值约为1.5%～2.0%,并由此计算出紫外法测定塔拉单宁含量计算公式中的矫正常数p为1.03。紫外-可见吸收光谱与HPLC分析结果表明：塔拉单宁与五倍子单宁的最大吸收峰均为276 nm,同质量浓度下塔拉单宁的吸收峰强度高于五倍子单宁，塔拉单宁成分出峰时间主要在20～40 min,五倍子单宁主要在30～45 min。

Comparison on the Determination of Tara Tannin Content with UV Spectrophotometry and Hide Powder Method

Five kinds of tara tannin with different contents were determined and compared by UV spectrophotometry and hide powder method, and the significance test of tannin content determination results was carried out by SPSS software. The results showed that there was no significant difference in the determination of tannin content of high-puritytaratannin(93%) measured by UV spectrophotometry and hide powder method(P>0.05).However, the experimental results of the four kinds of tara tannins with the content of 60% have significant differences(P < 0.05), and the tannin contents measured by hide powder method were all higher than those measured by UV spectrophotometry, where the difference was about 1.5%-2.0%. And the correction constant i.e., p=1.03, in the formula for determining the taratannin content by UV method was calculated. The results of UV-Vis absorption spectrum and high performance liquid chromatography analysis showed that the maximum absorption peaks of tara tannin and gallic tannin were both at 276 nm. At the same mass concentration, the absorption peak intensity of tara tannin was higher than that of gallic tannin. The peaking time of tara tannin was mainly in 20-40 min, and the peaking time of gallic tannin was mainly in 30-45 min.