气相色谱法测定食盐中的碘含量

Determination of iodine in salt by gas chromatography

中文关键词:  碘  食盐  气相色谱法

英文关键词:iodine  salt  gas chromatography

中文摘要:

      目的 建立气相色谱法测定食盐中碘含量的分析方法。方法 在酸性条件下, 食盐中的碘在过氧化氢的氧化作用下, 与丁酮生成衍生物碘丁酮, 气相色谱的分离, 电子捕获检测器(election capture detector, ECD)检测。探究衍生剂的用量、衍生时间, 并对未加碘食盐和强化碘食盐进行检测及方法间比对。结果 在10~120 μg/L线性范围内回归系数r=0.9998, 检出限为0.002 mg/kg(S/N≥3), 定量限为0.006 mg/kg(S/N≥10), 相对标准偏差RSD范围为1.5%~3.2% (n=6), 加标回收率在91.3%~112.8%之间。与氧化还原滴定法进行方法间比对, 单一样本t检验分析无显著性差异。结论 该方法操作简单快捷, 结果灵敏度高、准确度和精密度好, 适用于食盐中碘含量的测定。

英文摘要:

      Objective To establish a method for the determination of iodine content in salt by gas chromatography. Methods Under acidic conditions, iodine in salt was oxidized by hydrogen peroxide to form a derivative iodobutane with butanone, which was separated by gas chromatography and detected by electron capture detector (election capture detector, ECD). This study explored the dosage of derivatizing agent, derivatization time, detection of iodized salt and fortified iodized salt and comparison between methods. Results In the linear range of 10~120 μg/L, the regression coefficient was 0.9998. The limit of the detection was 0.002 mg/kg (S/N≥3) and the limit of quantification was 0.006 mg/kg (S/N≥10). The relative standard deviation (RSD) was between 1.5%–3.2% (n=6), and the recovery rate was between 91.3%–112.8%. Compared with redox titration method, there was no significant difference in single sample t test analysis. Conclusion This method is simple and quick to operate, with high sensitivity, accuracy and precision, which is suitable for the determination of iodine content in salt.