毛细管电泳法分离测定食品中山梨酸、苯甲酸、糖精

采用毛细管电泳-紫外检测法，考察了波长，电压，缓冲试剂、浓度、pH对山梨酸、苯甲酸、糖精分离的影响，得到了优化的实验条件．以硼砂20mmol／L(pH=7．5)为运行缓冲溶液．20kV为分离电压，检测波长为230nm的电泳条件下，进样时间为10s，山梨酸、苯甲酸、糖精可在12min内实现分离．山梨酸在5mg／L～50mg／L，苯甲酸在5mg／L～50mg／L，糖精在15mg／L～150mg／L范围内呈良好线性关系，迁移速度、峰面积相对标准偏差均小于4．5％，(n=5)．用上述方法对实际样品进行测定，回收率在95％以上．

Separation and determination of sorbic acid,benzoic acid,saccharin in food by capillary electrophoresis

A new method for determination of sorbic acid, benzoic acid, and saccharin in food was developed by capillary electro-phoresis with UV detection. The main effect factors on the separation, the separation voltage,the composition of the running buffer solution and its pH, as well as the waves length of the UV detector, were optimized. With 20 mmol/L borax (pH=7.5) running buffer solution, 20 kV of the separation voltage, and 230 nm of the detection wave length, the above substances could be separated within 12 min. Under such optimum conditions, the linear ranges for sorbic acid, benzoic acid, and saccharin are 5 mg/L-50 mg/L, 5 mg/L-50 mg/L, and 15 mg/L-150 mg/L, respectively, and the relative standard deviation was less than 4.5%. The recovery of this method to the real samples was found to be better than 95%.