柱后衍生-高效液相色谱-荧光检测法测定面粉中的过氧化苯甲酰

利用过氧化苯甲酰能够在氯化血红素的催化下将底物对羟基苯乙酸氧化成具有荧光的二聚体的性质,建立了柱后衍生-高效液相色谱-荧光检测法测定面粉中过氧化苯甲酰的方法。优化了色谱分离条件和柱后衍生条件,结果表明:催化剂氯化血红素的浓度为8μmol/L,底物对羟基苯乙酸的浓度为80μmol/L,衍生化试剂的pH 10.5,衍生温度为35℃时衍生效率最高。在优化条件下,过氧化苯甲酰的线性范围为0.5～100 mg/L;样品的检出限为1 mg/kg,样品的加标回收率为98.5%～99.5%。本方法与现有的高效液相色谱法相比,检测面粉中过氧化苯甲酰具有抗干扰能力强,灵敏度高。

Determination of Benzoyl Peroxide in Wheat Flour by Post-column Derivatization-High PerformanceLiquid Chromatography with Fluorescence Detection

A method for the determination of benzoyl peroxide in wheat flour by post-column derivatization-high performance liquid chromatography with fluorescence detection was developed based on the reaction that the p-hydroxyphenylacetic acid can be oxidized to the fluorescent dimer by benzoyl peroxide with hemin as catalyzer.The optimum derivatization efficiency was obtained with the hemin and p-hydroxyphenylacetic acid concentration at 8 μmol/L and 80 μmol/L,respectively,with the derivatization reagent pH at 10.5 and the derivatization temperature at 35 ℃.The linear range between 0.5 mg/L to 100 mg/L was observed for the established method.The sample detection limit was 1 mg/kg and standard spike recoveries were 98.5%-99.5% under the optimized conditions.The obvious advantages of excellent anti-jamming capability and high-sensitivity were observed comparing with other HPLC methods for determination of benzoyl peroxide.