【摘要】 在稀硫酸介质中,碘离子能快速、定量地还原高锰酸根,在加入碘离子前后,高锰酸钾溶液在波长525nm处的吸光度发生显著变化,且吸光度之差△A与加入的碘离子的浓度成正比,确定了最佳反应条件,建立了高锰酸根褪色光度法测定食盐中微量碘离子的新方法。方法的线性范围为0～20μg/mL,线性回归方程为△A=0.0165c+0.0041,相关系数r=0.9987,检出限为0.17μg/mL。用于食盐中微量碘离子的测定,加标回收率为91.0％～95.0％,相对标准偏差为0.35％～0.75％。更多还原

【Abstract】 In diluent sulfuric acid medium, permanganate can be reduced by iodine ion very quickly. The absorbance of potassium permanganate solution at 525 nm would change significantly when iodine ion presents in the solution, and the difference of ab-sorbances is in direct proportion to iodine ion concentration. The optimum reaction conditions were defined, a new method of determining iodine ion by pormanganate fading spectrophotometry was set up. The linear range is 0~20μg/mL, the linear regressive equation is A=0. 016 5c + 0. 004 1, the correlative coefficient is 0.998 7 , and the detection limit is 0. 17 μg/mL. The method has been used in the determination of iodine ion in table salt, the recovery is 91.0%~95.0%, the relative standard deviation is 0. 35%-0.75%.更多还原