Russell Ben C, Warwick Phil E, Croudace Ian W
GAU-Radioanalytical, Ocean and Earth Science, University of Southampton, National Oceanography Centre , Southampton SO14 3ZH, United Kingdom.
Anal Chem. 2014 Dec 2;86(23):11890-6. doi: 10.1021/ac5036988. Epub 2014 Nov 18.
Advances in the sensitivities achievable by sector field inductively coupled plasma mass spectrometry (ICP-SFMS) offer the prospect of low-level measurement of shorter and longer lived radionuclides, thus expanding options for environmental and radioactively contaminated land assessment. In ICP-SFMS, the critical requirement for accurate detection is the effective chemical separation of isobaric and polyatomic interferences prior to sample introduction. As instrumental detection limit capability improves, accurate radionuclide determination requires highly effective separation materials that combine high analyte selectivity with subsequent quantitative analyte recovery compatible with ICP-SFMS detection. Two radioactive isotopes measurable by ICP-SFMS are the high yield fission products (135)Cs and (137)Cs that have entered the environment as a result of anthropogenic nuclear activities. ICP-SFMS enables reliable measurement of (135)Cs/(137)Cs ratios, which can be used as a forensic tool in determining the source of nuclear contamination. The critical requirement for accurate detection is the effective removal of isobaric interferences from (135)Ba and (137)Ba prior to measurement. A number of exchange materials can effectively extract Cs; however, non-quantitative elution of Cs makes subsequent ICP-SFMS quantification challenging. A novel extraction chromatographic resin has been developed by dissolving calix[4]arene-bis(tert-octylbenzo-crown-6) (BOBCalixC6) in octan-1-ol and loading onto an Amberchrom CG-71 prefilter resin material. Preparation of the material takes less than 1 h and, at an optimal concentration of 3 M HNO3, shows high selectivity toward Cs, which is effectively eluted in 0.05 M HNO3. The procedure developed shows high Cs selectivity and Ba decontamination from digests of complex matrixes including a saltmarsh sediment contaminated by aqueous discharges from a nuclear fuel reprocessing facility. Repeated tests show the resin can be reused up to four times. For low-level ICP-SFMS quantification, more complex sample matrixes benefit from a cation resin cleanup stage prior to using BOBCalixC6 that serves to enhance Ba decontamination and Cs recovery.
扇形磁场电感耦合等离子体质谱仪（ICP-SFMS）在灵敏度方面的进展为短寿命和长寿命放射性核素的低水平测量提供了可能，从而为环境和放射性污染土地评估拓展了选择。在ICP-SFMS中，准确检测的关键要求是在进样前有效化学分离同量异位素和多原子干扰。随着仪器检测限能力的提高，准确测定放射性核素需要高效的分离材料，这种材料要兼具对分析物的高选择性以及与ICP-SFMS检测兼容的后续分析物定量回收能力。两种可通过ICP-SFMS测量的放射性同位素是高产率裂变产物（135）Cs和（137）Cs，它们因人为核活动而进入环境。ICP-SFMS能够可靠地测量（135）Cs/（137）Cs比值，该比值可用作确定核污染来源的法医工具。准确检测的关键要求是在测量前有效去除来自（135）Ba和（1）Ba的同量异位干扰。许多交换材料能有效萃取Cs；然而，Cs的非定量洗脱给后续的ICP-SFMS定量分析带来了挑战。通过将杯[4]芳烃双（叔辛基苯并 - 冠 - 6）（BOBCalixC6）溶解在1 - 辛醇中并负载到Amberchrom CG - 71预过滤树脂材料上，开发出了一种新型萃取色谱树脂。该材料的制备耗时不到1小时，在3 M HNO3的最佳浓度下，对Cs表现出高选择性，能在0.05 M HNO3中有效洗脱。所开发的方法对Cs具有高选择性，并且能从包括受核燃料后处理设施排放水污染的盐沼沉积物在内的复杂基质消化物中去除Ba。重复测试表明该树脂可重复使用多达四次。对于低水平的ICP-SFMS定量分析，在使用BOBCalixC6之前，更复杂的样品基质受益于阳离子树脂净化步骤，这有助于增强Ba的去污效果和Cs的回收率。
