METHODS The hydroxyl groups of magnolol were protected using ketol reaction and the products were purified by recrystallization from hexane.

方法将朴酚两羟基用缩酮保护,再用正重结晶分离纯。

The perservative in liquid beverage was extrcated with n-hexane.The hexane layer was subjected to cyclodextrine polymer resin colume.The colume was eluted with aqueous solution of ethanol.

用正萃取体饮料中的防腐剂，使萃取经环糊精交联树脂分离后，用乙醇脱。