Based on derivative reaction between iodide and propylene oxide, we established a method for determining trace iodide in grain formula foods by gas chromatography. Under the optimum conditions, the iodide concentration had a linear relationship with the peak area of iodinated derivatives in the range of 0.202 9 to 2.029 μg/10 mL, and correlation coefficient was 0.999 5; the standard deviation of iodide content in the product after repeated determined was 0.014 μ g/g, the coefficient of variation was 6.26%, and determination limit was 0.002 μ g/g; and the standard recovery was from 99.6% to 110.9%, and the mean recovery was 106.4%. The method was simple, was immune to the interference of grain starch, and was particularly suitable for determination of trace iodide in infant grain formula foods.%通过对碘离子与环氧丙烷衍生反应、气相色谱法测定条件的研究,建立了一种谷物配方食品中痕量碘化物的测定方法.在最佳测定条件下,碘离子在0.202 9 ～ 2.029 0μg/10 mL浓度范围内与碘代衍生物峰面积呈线性相关,相关系数R=0.999 5；样品中碘含量重复测定标准偏差0.014 μg/g,变异系数6.26％,检测限0.002 μg/g;样品加标回收率99.6％～110.9％,平均106.4％.该方法操作简单,不受谷物淀粉干扰,特别适用于婴幼儿谷物配方食品中痕量碘含量的测定.
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