压力罐消解-氢化物原子荧光光谱法测定婴儿配方乳粉中硒的方法探讨

Discussion on the determination of selenium in infant formula milk powder by pressure tank digestion-hydride atomic fluorescence spectrometry

中文关键词:  婴儿配方乳粉  硒  压力罐消解法  氢化物原子荧光光谱法  铁氰化钾

英文关键词:infant formula milk powder  selenium  pressure tank digestion  hydride atomic fluorescence spectrometry  potassium ferricyanide

中文摘要:

      目的 探讨压力罐消解-氢化物原子荧光光谱法测定婴儿配方乳粉中硒的测定条件。方法 通过压力罐消解和微波消解对比实验、样品重复性实验, 用氢化物发生原子荧光光谱(hydride generation atomic fluorescence spectrometry, HG-AFS)和电感耦合等离子体质谱(inductively coupled plasma mass spectrometry, ICP-MS)测定的结果相互比对, 确定压力罐消解的可行性以及消解最佳温度; 通过测定10 μg/L硒溶液和一系列含不同浓度干扰元素的10 μg/L硒溶液中硒的荧光强度, 计算硒含量的回收率, 并与各元素在婴儿配方乳粉中的最高限量对比, 讨论HG-AFS法测定时添加铁氰化钾的不必要性。结果 采用压力罐消解, 消解温度为160 ℃时, HG-AFS法和ICP-MS法的测定结果无显著差异, 精密度分别为1.95%和1.49%; 在其他必需矿物质元素含量符合限量要求时, 各元素对HG-AFS法测定硒的含量没有干扰。结论 压力罐消解法适合于作为HG-AFS法测定婴儿配方乳粉中的硒的前处理方法, 该方法操作简单, 稳定性好, 试剂消耗量少, 适合处理大批量样品; HG-AFS法测定婴儿配方乳粉中的硒不必添加铁氰化钾。

英文摘要:

      Objective To investigate the conditions for determination of selenium in infant formula milk powder by pressure tank digestion-hydride atomic fluorescence spectrometry. Methods Through contrast test of pressure tank digestion and microwave digestion and sample repeatability test, the measurement results by hydride generation atomic fluorescence spectrometry (HG-AFS) and inductively coupled plasma mass spectrometry (ICP-MS) were compared, to determine the feasibility of pressure tank digestion and the optimal temperature of digestion. The fluorescence intensity of selenium in a 10 μg/L selenium solution and a series of 10 μg/L selenium solutions containing different concentrations of interfering elements was determined. The recovery of selenium was compared with the maximum amount of each element in the infant formula milk powder for discussing the necessity of adding potassium ferricyanide when determined by HG-AFS method. Results The results of the HG-AFS method and the ICP-MS method showed no significant difference when the digestion temperature was 160 ℃. The precision was 1.95% and 1.49%, respectively. When the content of other essential minerals was within the limit, the elements did not interfere with the determination of selenium by HG-AFS. Conclusion The pressure tank digestion method as a pretreatment method is suitable for the determination of selenium in infant formula milk powder by HG-AFS. The method is simple in operation, good in stability and low in reagent consumption, which is suitable for processing large quantities of samples and it is not necessary to add potassium ferricyanide to determine selenium in infant formula milk powder by HG-AFS.