面粉、面制品中过氧化苯甲酰的测定及还原剂的选择

Determination of benzoyl peroxide in flour and flour products and the selection of reducing agents

目的在推荐方法的基础上改进并建立高效液相色谱法测定面粉及面制品中过氧化苯甲酰的方法。方法以乙腈-0.01mol/L醋酸铵溶液为流动相,优化色谱分离条件,选择合适的还原剂碘化钾溶液浓度,并以碘化钾溶液的还原能力做对照,比较五种实验室常用还原剂对过氧化苯甲酰的还原效率及色谱分离情况。结果在选择的分离条件下,以10%碘化钾做还原剂,方法的线性范围为0.01mg～0.15mg,最低检出量为0.8ng,相关系数大于0.9996,平均加标回收率介于92.4%～105.3%之间,相对标准偏差为2.3%～4.3%。10%亚硫酸氢钠、10%硫代硫酸钠、10%亚铁氰化钾均可作为转化反应的还原剂。结论所建立的方法灵敏度高,分离效果好。实验室人员可根据情况选择适当的还原剂。

Objective To improve and develop a method for the determination of benzoyl peroxide （ BP ） in flour and flour products by reverse - phase high - performance liquid chromatography （ RP - HPLC ） based on the recommendatory methods. Method The conditions of chromatography seperation were optimized with the mobile phase comprising of acetonitrile and 0.01moL/L ammonia acetate. The different concentrations of potassium iodide as reducer to reduce benzoyl peroxide to benzoic acid were tested and choosed, and the reducing efficiencies and chromatography seperation of five common reducing agents were compared with potassium iodide. Results Under the selected chromatography seperation conditions and 10% potassium iodide solution as reducer, good linearity was obtained in the range of 0.01 and 0. 15mg of benzoyl peroxide with the correlation coefficient 0. 9996, the limit of detection was 0.8ng, the mean spiked recoveries were between 92.4% and 105.3 %, and the relative standard deviations were within 2.3 %～ 4. 3%. The experimental results demonstrated that 10% sodium bisulfite solution, 10% sodium thiosulfate solution and 10% potassium ferrocyanide could also be reducing agents of benzoyl peroxide. Couclution The method developed has high sensitivity and good resuits of chromatography seperation. Lab assistants can choose available reducing agent to reduce benzoyl peroxide to benzoic acid according to own laboratory facts.