目的探讨取代剧毒试剂三氧化二砷(AS2O3)的水中碘的催化分光光度法。方法在稀硝酸介质中,研究碘催化硫氰酸铁褪色反应的适宜条件,建立测定水中微量碘含量的催化动力学光度法。结果方法的线性范围为6~100μg/L,相关系数r=-0.9997,检出限为1.77μg/L碘(取样量1mL,1.77ng碘),回收率在97.20%~99.95%。结论本方法较砷铈催化分光光度法检测水中碘的精密度和准确度结果满意,可完全不使用剧毒物质三氧化二砷,减小了对检测人员健康的损害和环境污染的风险。 Objective To investigate the catalytic spectrophotometry of iodine in water to replace arsenic trioxide (AS2O3), a highly toxic reagent. Methods In dilute nitric acid medium, the suitable conditions of iodine-catalyzed iron thiocyanate fading reaction were studied, and a catalytic kinetic spectrophotometry was established for the determination of trace iodine in water. Results The linear range of the method was 6-100 μg / L with a correlation coefficient of r = -0.9997. The detection limit was 1.77 μg / L iodine (sample volume was 1 mL and 1.77 ng iodine). The recoveries ranged from 97.20% to 99.95%. Conclusion The method is better than the arsenic cerium catalytic spectrophotometry to detect the precision and accuracy of iodine in water. The method can completely eliminate the use of highly toxic arsenic trioxide and reduce the risk of damage to human health and environmental pollution.