胶束毛细管电泳在线吹扫富集技术测定面粉中的增白剂过氧化苯甲酰

建立了测定面粉中过氧化苯甲酰含量的一种新方法。面粉用甲醇超声萃取,过滤,直接进样分析。在电泳缓冲液为0.02 mol/L硼砂-硼酸缓冲液（含0.04 mol/L十二烷基硫酸钠）(pH 9.0)、紫外检测波长为214 nm、分离电压为10 kV的条件下,富集倍数可达150倍以上,过氧化苯甲酰的质量浓度和其色谱峰高呈良好的线性关系,过氧化苯甲酰的线性 范围为0.002～0.012 g/L(r=0.9998),最低检测限为2 mg/L。将该法用于面粉中过氧化苯甲酰的分析,样品无需繁琐的预处理过程便可直接定量,缩短了分析周期,简单方便,重现性好。

Determination of Benzoyl Peroxide in Wheat Flour by Micellar Capillary Electrophoresis On-Line Sweeping Concentration Technique

A method for the determination of benzoyl peroxide in wheat flour was established by a micellar capillary electrophoresis on-line sweeping concentration technique. Benzoyl peroxide was ultrasonically extracted with methanol, filtrated by nylon membrane (0.45 microm), and analyzed directly by capillary electrophoresis. The conditions of pH of background solution, the concentration of sodium dodecyl sulfate (SDS) and injection time were investigated. The results demonstrated that the optimum separation efficiency can be obtained by using a running buffer of 0.02 mol/L borax-boric acid containing 0.04 mol/L SDS (pH 9.0), UV detection at a wavelength of 214 nm and an applied voltage of 10 kV. These conditions allowed up to 150-fold concentration of benzoyl peroxide and a linear correlation of benzoyl peroxide was obtained in a range from 0.002 g/L to 0.012 g/L. The detection limit was 2 mg/L. The results also showed that the method is precise, simple, and cost-effective.