放大反应-氯化钠增敏光度法测定食品中的微量碘

Determination of Trace Amounts of Iodine in Food by Magnification Reaction-Sodium Chloride Sensitizing Spectrophotometry

样品中的有机碘高温灰化后，在酸性条件下，经饱和溴水将I^-氧化为IO3^-.在0．06％的磷酸酸度条件下，以KI还原KIO3，使样品中的碘放大六倍。系统优化选择了定波长、磷酸酸度、氯化钠质量浓度、淀粉用量、碘化钾用量等。在选定的最佳实验条件下，碘质量浓度在0～3．2μg／mL范围旱良好线性关系，相关系数为0．9995；方法榆出限为0．028μg／mL，回收率为96．27％～106．43％。

After organic iodine in samples was burned at high temperature, I^- was oxidized to IO3^- by saturated bromine water under acidic condition, then with KI reduction KIO3 under 0.06% H3PO4, so the content of iodine in samples was magnified to six times. Some parameters were optimized, including wavelength, pH, concentration of NaCl, starch and KI, etc. The results show that under the optimum experimental conditions, its linear range is 0 -3.2 μg/mL, the detection limit and recoveries are 0. 028 μg/mL, 96. 27% - 106.43%.