阻抑动力学光度法测定海带和紫菜中微量碘

Inhibition Kinetic Spectrophotometric Determination of Micro Amount of Indine in Kelp and Lavel

文章基于在硝酸介质中,硫代硫酸钠存在下,痕量碘离子对溴酸钾氧化次甲基兰使其褪色的抑制作用,建立了测定微量碘的新方法。测定碘离子线性范围为0.01-0.2μgmL-1,检出限为0.0062μgmL-1,用于海带和紫菜中微量碘的测定。

The determination of iodine in food is important due to the function of iodine of keeping body health. A rapid, simple and sensitive catalytical kinetic method is developed for the determination of iodine. The method is based on the inhibitory action of iodide ion on the decoloration of methylene blue oxidized by potassium bromate catalyzed by sodium thiosulfate in nitrate acid medium. The linear ranges of determination are 0.01 -0.2μgmL^-1, and the detection limits are 0. 0062 μgmL^-1. The developed method has been used for the determination of micro amounts of iodine in kelp and lavel with satisfactory results.