Abstract: A gas chromatographic method for determining the iodine content in milk powder was established, and the homogeneity and stability of iodine reference material were evaluated. Butanone derivative with iodine produced under acidic conditions was detected by gas chromatography (GC) with an electron capture detector and quantified by an external standard method. The proposed method showed a good linear relationship (R2 = 0.999 6), the recoveries from spiled samples were between 95.3% and 101.3%, and the relative standard deviation (RSD) was 2.3% (n = 6). This method had high accuracy and could be used for the determination of the iodine content in milk powder.

Key words: gas chromatography; milk powder; iodine; reference material; characterization

摘要： 建立一种基于气相色谱法的牛乳粉中碘成分分析基体标准物质定值方法，并将此方法用于该标准物质的均匀性和稳定性检验，对其进行定值。碘在酸性条件下与丁酮反应生成丁酮与碘的衍生物，经气相色谱仪的电子捕获检测器检测，外标法定量。结果表明：该方法线性关系良好（R2=0.999 6），加标回收率为95.3%～101.3%，相对标准偏差为2.3%（n=6）。该方法准确度高，可用于牛乳粉中碘含量的标准物质定值。

关键词: 气相色谱法；牛乳粉；碘；标准物质；定值