A new inhibition kinetic spectrophotometric method for the determination of trace iodine in edible salt is proposed.This method is based on the inhibition effect of iodide on the oxidation of aniline blue by potassium bromate in the presence of sulfuric acid.The effects of reaction parameters such as acidity,reagent consumption,temperature and time are investigated and optimized.Under the optimum conditions,the calibration curve is linear in the range of 8~48μg/L with the detection limit of 1.3×10-6 g/L.The developed method is simple,sensitive and selective,which can be applied for the determination of trace iodine in edible salt with satisfactory results.%在硫酸介质中,痕量碘离子对溴酸钾氧化苯胺蓝褪色反应有显著的阻抑作用,据此建立阻抑动力学光度法测定微量碘的新方法。研究了褪色反应的动力学参数包括酸度、试剂的用量、温度和时间等,确定了最优化的反应条件。方法的线性范围为8~48μg/L,检测限为1.3×10-6 g/L。该方法操作简便、灵敏度高、选择性好,用于食盐中微量碘的测定,取得满意的结果。
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