动力学分光光度法测定海盐中的痕量碘

Spectrophotometric Determination of Iodide by a Differential Kinetic Method

在硫酸介质中 ,基于高碘酸钾氧化碘离子生成碘 ,进而使次甲基蓝褪色的反应 ,建立了测定痕量碘的新方法 .线性范围为 0μg/ m L～ 7.2μg/ m L ,检出限为 0 .33μg/ m L.方法简便、灵敏、选择性好 ,用于海盐中痕量碘的测定 ,结果满意 .

A rapid, simple and sensitive differential kinetic method is presented for the determination of iodide. The method is based on reaction between iodide and periodates in the presence of methylene blue. The reaction can be monitored spectrophotometrically by measuring the decrease in absorbance at 665 nm. Two sets of conditions were established that in one set of conditions only periodate without iodide but in the other set the two ions reacted. The data were evaluated by proportional equations. The method allowed the determination of iodide at concentrations between 0μg/mL and 7.2μg/mL. The method was applied to the determination of iodide in sea salt with satisfactory results.