毛细管电泳法分离检测饮料中的防腐剂

采用高效毛细管电泳法,同时在线分离检测对羟基苯甲酸甲酯、山梨酸钾和苯甲酸3种防腐剂。考察了运行缓冲液的浓度、pH值、分离电压、进样时间等因素对电泳分离的影响。在检测波长为230nm时,获得了3种防腐剂分离检测的最优化实验条件为:20mmol/L pH 9.2的硼砂缓冲溶液,分离电压为22kV,进样时间15s。在最优化实验条件下,3种防腐剂检测的线性相关系数均大于0.98,检出限为1.0×10-2g/kg。利用此方法检测了市售3种饮料中所含防腐剂的种类和含量,各种防腐剂的回收率在88%~102%之间。

Separation and detection of preservatives in beverage by capillary electrophoresis

A high performance capillary electrophoresis method was developed for the simultaneous determination of three kinds of preservatives, such as methylparaben, potassium sorbate and benzoic acid. The effect of running buffer concentration, pH, separation voltage, sampling time on electrophoretic separation was investigated. At the detection wavelength of 230 nm, the optimal separation and detection of three preservatives condi- tions were optimized as follows： 20 mmol/L sodium borate buffer at pH 9.2, running voltage 22 kV and sampling time 15 s. Under the optimized con- dition, the linearly dependent coefficients of three preservatives were all greater than 0.98, and the detection limits was 1 x 10-2 g/kg. The method has been successfully used for determination of preservatives in three kinds of beverages, and the recoveries of the preservatives were between 88%- 102%.