光度法测定小麦面粉中过氧化苯甲酰

Photometric Determination of Benzoyl Peroxide in Wheat Flour

在磷酸介质中,过氧化苯甲酰氧化碘化钾生成的碘与淀粉显色,在585 nm波长处有最大吸收峰,建立了碘化钾碘蓝光度法间接测定微量过氧化苯甲酰的方法。过氧化苯甲酰的质量浓度在0.016 g.L-1以内呈线性。方法应用于新出产的小麦面粉中过氧化苯甲酰的测定,回收率在93.3%以上。

In a dil. H3PO4 solution, potassium iodide was oxidized by benzoyl peroxide to give iodine quantitatively. A blue colored complex was formed by the reaction of the liberated iodine with starch, and its absorption measured at 585 nm, the absorption maximum of the blue colored complex. Linear relationship was kept within 0. 016 g ·L^-1 of benzoyl peroxide. As an indirect photometric method for the determination of microamounts of benzoyl peroxide, it was applied to the analysis of wheat flour samples, and values of recovery over 93. 3% were obtained.