摘要
目的探讨氧化还原滴定法检测川盐含碘量的可行性分析及其控制方法，用以提高检测质量。方法在四川省4个县（区）内抽取122份盐样，检测盐样中碘离子形态。省级和县级疾病预防控制中心实验室采用氧化还原滴定法检测盐样含碘量．对结果进行实验室间比对。省级疾病预防控制中心分别用氧化还原滴定法和溴水氧化滴定法检测盐样含碘量，对结果进行方法间比对。检测比较不同存放方式（敞口、封闭）和存放时间（第1、2、4、7、14、30、60天）次氯酸钠试剂中有效氯水平。结果川盐在运输和储存的过程中碘离子的形态可由碘酸根离子（103^-）向碘离子（I^-）转化；省级与县级疾病预防控制中心实验室氧化还原滴定法检测的122份盐样含碘量分别为（32．40±8．44）、（31．10±8，34）mg／kg，122对检测结果的数据差值为1．33mg／kg，差值绝对值≤1mg／kg的占18．8％（23／122），〉1～3mg／kg的占23．0％（28／122），〉3～5mg／kg的占23．0％（28／122），〉5～10mg／kg的占26，2％（32／122）。〉10mg／kg的占9．0％（11／122）。次氯酸钠开瓶后敞口和密闭存放60d，有效氯水平分别下降43．6％和32．5％：氧化还原滴定法和溴水氧化滴定法检测的114份盐样含碘量分别为（32．60±8．44）、（32，50±8．18）mg／kg，两种方法检测结果比较，差异无统计学意义（t=0．282，P〉0．05）。结论川盐在储运过程中碘酸钾可向碘化钾转化。在氧化还原滴定法检测川盐含碘量过程中，次氯酸钠的有效氯水平和用量影响较大且不易控制，推荐使用溴水氧化滴定法检测川盐含碘量。
Objective To investigate the influential factors and the control measures thereof iodine salt detection with oxidation-reduction titration method so as to improve the detection quality. Methods 122 samples were ohtained randomly from four counties （districts） of Sichuan Province to determine iodine ions forms. In center for diseases control and prevention （CDC） laboratories at the provincial and county levels, iodine contents in the samples were determined with oxidation-reduction titration and the results were compared between laboratories. The provincial laboratory also employed bromine water oxidation for method comparison. Also the volume fractions of chlorine available were determined in sodium hypochlorite storage in open or sealed status and of different storage periods of 1 ,2,4,7,14,30 and 60 days. Results The iodine transformed from IO3^- to I^- during the shipment and storage; The iodine contents in the 122 salt samples determined by the laboratories at the provincial and county levels were respectively （32.40 ± 8.44）, （31.10 ± 8.34）mg/kg with a result discrepancy of 1.33 mg/kg. Of all the absolute discrepancy values, 18.8%（23/122） were lower than or equal to 1 mg/kg; 23.0%（28/122） were equal to or higher than 3 mg/kg; 23.0%（28/122） were lower than or equal to 5 mg/kg; 26.2%（32/122） were lower than or equal to 10 mg/kg; 9.0% （11/122） were higher than 10 mg/kg. After the bottles were opened and stood for 60 days, the available chlorine content in the sodium hypoehlorite decreased by 43.6% and 32.5% respectively in open and sealed status. Iodine contents were respectively （32.60 ± 8.44）, （32.50 ± 8.18）mg/kg（n = 114） with the oxidationreduction titration method and bromine water oxidation method, and no significant difference was found between the results of the two methods （t = 0.282, P 〉 0.05 ）. Conchlsions Potassium iodate in salt in Sichuan is prone to transform into potassium iodide during shipping, so when determining salt iodine with the oxidation-reduction titration method, the content and the amount of chlorine available in the sodium hypoehlorite differ a lot and are difficult to control. Therefore, bromine water oxidation titration is recommended.
出处
《中国地方病学杂志》
CAS
CSCD
北大核心
2008年第3期317-319,共3页
Chinese Jouranl of Endemiology
关键词
碘
盐类
氧化还原
Iodine
Salts
Oxidation-reduction
