利用大孔树脂吸附法分离儿茶素EGCG和咖啡因

Elimination of Caffeine from Catechins EGCG by Macroporous Adsorption Resins

考察了S-8、X-5、XAD-200等树脂对绿茶水提液中儿茶素EGCG和咖啡因的吸附性能,结果显示,具有高比表面积的弱极性吸附树脂XAD-200对EGCG和咖啡因的吸附差异较大,动态吸附过程中发生层析分离,儿茶素EGCG在1.5 BV后即开始泄漏,而咖啡因在6 BV后才开始泄漏.收集1.5～6 BV处的流出液可得w（咖啡因）＜0.30％的儿茶素,EGCG的质量分数由48.65％提高至66.37％.在最佳上样量下,EGCG的收率可达65.21％.

The adsorption performances of S - 8, X - 5 and XAD - 200 resins for catechins EGCG were studied. The XAD -200 resin with high surface area and low polarity showed strong selective capacity to caf- feine which could be adsorpted on resin easily. EGCG leaked out at 1.5 BV, while caffeine leaked out at 6 BV. The outflowing solution of 1.5 -6 BV mainly contained EGCG with caffeine content lower than 0. 3%. The purity of EGCG was increased from 48. 65% to 66. 37% with a yield of 65.21% under optimal sample loading conditions.