【摘要】 在硫酸介质中,碘酸根能氧化溴邻苯三酚红使之褪色,且褪色的程度与碘酸根的存在量有关,从而建立了光度法测定碘的方法。有色溶液的最大吸收波长为510nm,碘的存在量在0～30μg/25ml范围内符合比耳定律,表观摩尔吸光系数ε=1.81×104L·mol-1·cm-1。方法简便、快速、选择性好,准确度高,用于测定食盐中微量碘时,结果满意。更多还原

【Abstract】 In a dilute sulfuric acid medium (pH 2.4), BPR is oxidized by IO-3, leading to the colorfading of the color reagent, or more explicitly causing a decrease of absorbance at 510nm, the wavelength of one of the two absorption peaks of BPR reagent. The magnitude of decrease of absorbance (ΔA) is proportional directly to the increase of concentration of IO-3 (expressed as I-) in the range 0 to 30μg per 25ml of solution. The apparent molar absorptivity (ε) is 1.81×104L·mol-1·cm-1. This method is simple, rapid, accurate and precise, and has been successfully used in the determination of iodine in table salt.更多还原