中草药凉茶中苯甲酸、山梨酸、对羟基苯甲酸酯类同时测定的方法研究

目的：建立一种应用高效液相色谱法同时测定中草药凉茶中五种防腐剂含量的新监测方法。方法：样品经ODS-C18层析柱固相萃取净化、分离,20 mmoL乙酸铵与乙腈为流动相,进行梯度洗脱。结果：可将五种防腐剂完全分离,在8～200μg/mL线性范围内（r均大于0.9999）,回收率在88.9%～110.8%之间,RSD在1.18%～6.82%之间（n=6）。最低检出限分别为：2.66×10-4、3.36×10-4、7.36×10-4、3.88×10-4、3.12×10-4 mg/kg;最低定量限分别为：1.33×10-3、1.68×10-3、3.68×10-3、1.94×10-3、1.56×10-3 mg/kg。结论：通过对样品前处理条件的选择和优化,能较好地除去大部分杂质的干扰。本方法能满足中草药凉茶中苯甲酸、山梨酸、对羟基苯甲酸甲酯、对羟基苯甲酸乙酯、对羟基苯甲酸丙酯同时测定的要求,具有较好的推广意义;亦可作为监测儿童中药合剂和凉茶饮料防腐剂含量限制的参考。

Research on the Method of Simultaneously Determining Benzoic Acid, Sorbic Acid,Parabens in Herbal Tea

Objective： To set up a new monitoring methodology to simultaneously determine the content of the five preservatives contained in herbal tea by applying a HPLC.Method： The sample is to go through SPE purification and separation by chromatographic column ODS-C18;20 mmoL ammonium acetate and acetonitrile are the mobile phases;and gradient elution is adopted on the sample.Result： The five preservatives can be completely separated,with the linearity range within 8~200 μg/mL,the recovery rate between 88.9 % and 110.8 %,and RSD between 1.18 % and 6.82 %（n=6）.Minimum detectability are separately： 2.66×10-4,3.36×10-4,7.36×10-4,3.88×10-4 and 3.12×10-4mg/kg;while LOQ are 1.33×10-3,1.68×10-3,3.68×10-3,1.94×10-3,1.56×10-3mg/kg respectively.Conclusion： The disturbance from the mass of impurities can be nicely removed by the selection and optimization of samples before the proceeding of the determination procedure.The methodology is able to satisfy the requirements of simultaneously determining benzoic acid,sorbic acid,emthyl,ethyl and propyl parabenzoic acid in herbal tea;it was worthy of popularization;and it can be taken as a reference for the supervision of content limitation on preservatives contained in Chinese traditional medicine mixture or herbal tea for children.