聚酰胺/硅胶吸附剂吸附分离茶多酚的红外光谱
林种玉 傅锦坤 杨茹 古萍英 摘要 用傅里叶变换红外光谱研究了室温下聚酰胺/硅胶吸附剂(PA/SiO2)对茶叶中茶多酚的分离提取原理.红外光谱表明,PA/SiO2中PA分子的酰胺基是通过氢键吸附茶多酚分子的活性基团,而酰胺基对咖啡因分子没有吸附作用.PA/SiO2中SiO2表面羟基OH是吸附咖啡因及茶多酚分子的活性基团.由于氢键的作用,茶多酚和咖啡因分子之间也能相互吸附.PA/SiO2对氨基酸类物质不起吸附作用,因而容易将其分离. IR Absorption Spectra of Tea Polyphenol Extracted by PA/SiO2 Abstract The principle of tea polyphenol extracted by polyamide on silica adsorbent (PA/SiO2) at room temperature was studied with FTIR Spectroscopy. The obtained IR spectra showed that the amide group CONH- of the PA molecule of PA/SiO2 adsorbed the active group of tea polyphenol molecule through hydrogen bonding and did not adsorb the caffeine molecule. The surface hydroxyl group on the SiO2 of PA/SiO2 was the reactive group which adsorbed caffeine and tea polyphend molecules, and the tea polyphenol and caffeine molecules can also adsorb each othe via hydrogen-bonding. Substances like amino acids were not adsorbed by PA/SiO2 and thus easily separated. 茶叶中含有茶多酚、咖啡因及多种氨基酸等生物活性物质[1],其中茶多酚含量约占茶叶干重的22%.茶多酚是天然抗氧化剂,具有很强的清除自由基作用以及抑制癌变、脂质过氧化、抗衰老、抗辐射等多种生理功能[2].有关茶叶中茶多酚的分离提取研究国内外已有大量的文献报道[3~5].在这些研究基础上,我们开发研制了一种提取茶叶中茶多酚的PA/SiO2吸附剂[6],茶多酚提取率高于90%,纯度可达80%~90%;工艺简单,吸附剂可反复使用,且无污染环境问题,具有应用前景.本文用红外、紫外可见光谱研究了室温下该吸附剂与茶多酚、咖啡因和氨基酸(L_胱氨酸)之间的相互作用本质. 以上是 聚酰胺/硅胶吸附剂吸附分离茶多酚的红外光谱 的全部内容, 来源链接: utcz.com/cha/490381.html |