摘要目的 建立一种无砷自动检测饮用水中碘含量的流动注射测定方法.方法 在稀硝酸溶液中,碘离子在适量亚硝酸下能催化橙红色的硫氰酸铁络合物褪色,利用该原理结合流动注射分析技术建立了流动注射法,并优化该方法的实验条件.检测优化条件下该方法的标准曲线线性关系和线性范围、样品测定检测限、精密度和准确度.结果 经系列试验研究得出最佳的硫氰酸钾溶液(0.15 mol/L)和亚硝酸钠的加入量分别为27.30 ml和8.00 g/L;在该条件下,其标准曲线线性范围为0~500μg/L,标准曲线线性相关系数≥0.9990;方法检测限为5.94μg/L;对低、中、高3种浓度水碘做方法精密度实验,变异系数分别为1.19%、1.92%、2.06%;准确度试验中,加标回收率为100.49%~107.84%,总平均加标回收率为103.15%.结论 本流动注射法能较好地检测水中碘化物,在水样碘化物含量0~500μg/L范围内有良好的精密度和准确度,自动进样、自动加注试剂和自动检测体系减轻了检测人员的负担,无砷试剂使用又减少环境污染和对检测人员的健康危害,适用于高碘地区水碘筛查工作.

abstractsObjective To establish a method for automatic determination of iodine content in drinking water by flow injection analysis (FIA) without arsenic. Methods In the dilute nitric acid solution, iodide ion in appropriate amount of nitrous acid solution could catalyze the orange red iron thiocyanate complex fade, and the use of this method combined with flow injection analysis technology formulated a flow injection method, and experimental conditions of the method were optimized. The linear relationship and linear range of the standard curve, the detection limit, the precision and the accuracy of the sample determination were implemented under the optimized conditions. Results The optimum concentration of potassium thiocyanate solution (0.15 mol/L) and sodium nitrite was 27.30 ml and 8.00 g/L, respectively, by series of experimental studies. Under the condition, the linear range of the standard curve was 0-500μg/L, the standard curve linear relationship coefficient≥0.9990;method detection limit was 5.94μg/L; in precision experiment of low, medium and high concentrations of iodine, the coefficients of variation were 1.19%, 1.92%and 2.06%;in accuracy test, recovery rates were 100.49%-107.84%, and the total recovery rate was 103.15%. Conclusions The flow injection analysis method can be used to replace arsenic cerium catalyzed spectrophotometric detection of iodide in water; when the method is used in detection of the sample water iodide content of 0 - 500 μg/L, it has good precision and accuracy, automatic injection, automatic filling reagents and automatic detection system to reduce the burden on the staff, with arsenic-free reagents and reduced environmental pollution and the health hazards of the inspectors, which is suitable for iodine screening in high iodine areas.