表面活性剂增敏光度法测定食盐中的碘

建立了碘酸根-荧光黄-表面活性剂体系下测定食盐中碘的方法。采用增敏光度法研究在醋酸介质中，表面活性剂存在下，溴化钾催化KIO3氧化荧光黄的褪色反应。结果表明：最大吸收波长为438.5 nm，KIO3质量浓度在0.40～3.00 μg/mL范围内遵守朗伯-比尔定律，ΔA与KIO3质量浓度之间呈线性关系；438.5 nm波长条件下该反应的相关系数为0.999 0，表观摩尔吸光系数为4.31×104 L/（mol·cm）。用于测定食盐中微量的碘，相对标准偏差为0.83%～1.47%，回收率为98.1%～98.4%，此方法准确度较高，操作简便、快捷，是测定加碘食盐中碘含量较好的方法之一。

Determination of Iodine in Table Salt by Surfactant Sensitization Spectrophotometric Method

This paper describes a method for the determination of iodine in table salt using iodate-fluorescent yellowsurfactant
system. The conditions for the oxidation of fluorescent yellow by potassium iodate in acetic medium were studied.
The system had a maximum absorption at 438.5 nm in the medium of acetic acid. Beer’s law was obeyed in the range of
0.40–3.00 mg/L of iodine. The molar absorption coefficient was 4.31×104 L/(mol·cm) with a correlation coefficient of
0.999 0. The precision expressed as relative standard deviation (RSD) was in the range of 0.83%–1.47%, and the recoveries
were in the range of 98.1%–98.4%. This method is simple, rapid, accurate and precise, and has been successfully used in
determination of iodine in table salt.