WASTe Group, Institute of Inorganic Solid State Chemistry, Saarland University, Campus Dudweiler, Am Markt Zeile 5, D-66125 Saarbrücken, Germany.
WASTe Group, Institute of Inorganic Solid State Chemistry, Saarland University, Campus Dudweiler, Am Markt Zeile 5, D-66125 Saarbrücken, Germany.
Talanta. 2017 May 15;167:532-536. doi: 10.1016/j.talanta.2017.02.056. Epub 2017 Mar 6.
The determination of iodine as a main fission product (especially the isotopes I-129 and I-131) of stored HLW in a disposal beside its distribution as a natural ingredient of many different products like milk, food and seawater is a matter of particular interest. The simultaneous ICP-MS determination of iodine as iodide together with other elements (especially higher valent metal ions) relevant for HLW is analytically very problematic. A reliable ICP-MS quantification of iodide must be performed at neutral or alkaline conditions in contrast to the analysis of metal ions which are determined in acidic pH ranges. Herein, we present a method to solve this problem by changing the iodine speciation resulting in an ICP-MS determination of iodide as iodate. The oxidation from iodide to iodate with sodium hypochlorite at room temperature is a fast and convenient method with flexible reaction time, from one hour up to three days, thus eliminating the disadvantages of quantifying iodine species via ICP-MS. In the analysed concentration range of iodine (0.1-100µgL) we obtain likely quantitative recovery rates for iodine between 91% and 102% as well as relatively low RSD values (0.3-4.0%). As an additional result, it is possible to measure different other element species in parallel together with the generated iodate, even high valent metals (europium and uranium beside caesium) at recovery rates in the same order of magnitude (93-104%). In addition, the oxidation process operates above pH 7 thus offering a wide pH range for sample preparation. Even analytes in complex matrices, like 5M saline (NaCl) solution or artificial cement pore water (ACW) can be quantified with this robust sample preparation method.
碘作为储存高放废物中的主要裂变产物（特别是碘-129 和碘-131 同位素）的测定，以及其作为许多不同产品（如牛奶、食品和海水）的天然成分的分布，是一个特别关注的问题。同时测定碘作为碘化物以及其他与高放废物相关的元素（特别是高价金属离子）的电感耦合等离子体质谱法（ICP-MS）分析非常具有挑战性。与在酸性 pH 范围内测定金属离子不同，必须在中性或碱性条件下进行可靠的 ICP-MS 碘化物定量。本文介绍了一种通过改变碘形态来解决该问题的方法，从而实现了碘酸盐的 ICP-MS 测定。室温下用次氯酸钠将碘化物氧化为碘酸盐是一种快速、方便的方法，反应时间灵活，从一小时到三天不等，从而消除了通过 ICP-MS 定量碘形态的缺点。在所分析的碘浓度范围（0.1-100µgL）内，我们获得了碘的可能定量回收率在 91%至 102%之间，以及相对较低的 RSD 值（0.3-4.0%）。作为额外的结果，即使在高回收率（93-104%）下，也可以与生成的碘酸盐一起同时测量其他不同的元素物种，甚至是高价金属（铕和铀，以及铯）。此外，氧化过程在 pH 7 以上运行，因此为样品制备提供了广泛的 pH 范围。即使是复杂基质中的分析物，如 5M 盐水（NaCl）溶液或人工水泥孔隙水（ACW），也可以用这种稳健的样品制备方法进行定量。
