碱提取-电感耦合等离子体质谱法测定食品中的碘

Determination of iodine content in food by inductively coupled plasma-mass spectrometry with alkali extraction

中文关键词:  碘  电感耦合等离子体质谱  食品

英文关键词:iodine  inductively coupled plasma-mass spectrometry  food

中文摘要:

      目的 建立碱提取-电感耦合等离子体质谱法测定食品中碘含量。方法 样品经5%四甲基氢氧化铵(tetramethylammonium hydroxide, TMAH)溶液于85 ℃±5 ℃提取3 h, 离心后取上清液, 以铼作为内标, 采用电感耦合等离子体质谱法(inductively coupled plasma-mass spectrometry, ICP-MS)测定。结果 在0.5~50 μg/L的线性范围内, 回归方程呈现良好的线性关系, r=0.9998。该方法检出限为0.003 mg/kg, 定量限为0.01 mg/kg, 回收率为94%~102%之间, 相对标准偏差小于10%。结论 该方法操作简单, 灵敏度高, 适用于食品中碘含量的测定。

英文摘要:

      Objective To establish a method for determination of iodine content in food by inductively coupled plasma-mass spectrometry with alkali extraction. Methods Samples were extracted by 5% tetramethylammonium hydroxide (TMAH) at 85 ℃±5 ℃ for 3 h. The supernatants after centrifugal were determined by inductively coupled plasma-mass spectrometry (ICP-MS) with Re as internal standard. Results The calibration curve showed good linear relationship in the range 0.5-50 μg/L with good correlation coefficients (r=0.9998). The limit of detection was 0.003 mg/kg and the limit of quantification was 0.01 mg/kg. The spiked recoveries were 94%?102%, the relative standard deviation was less than 10%. Conclusion This method is simple and sensitive, it is suitable for the determination of iodine in food.