European Commission, Joint Research Centre, Institute for Transuranium Elements , P.O. Box 2340, D-76125 Karlsruhe, Germany.
Anal Chem. 2016 Sep 6;88(17):8862-9. doi: 10.1021/acs.analchem.6b02472. Epub 2016 Aug 11.
Employing a commercial high-resolution inductively coupled plasma optical emission spectrometry (HR-ICP-OES) instrument, an innovative analytical procedure for the accurate determination of the production age of various Pu materials (Pu powder, cardiac pacemaker battery, (242)Cm heat source, etc.) was developed and validated. This undertaking was based on the fact that the α decay of (238)Pu present in the investigated samples produced (234)U and both mother and daughter could be identified unequivocally using HR-ICP-OES. Benefiting from the high spectral resolution of the instrument (<5 pm) and the isotope shift of the emission lines of both nuclides, (234)U and (238)Pu were selectively and directly determined in the dissolved samples, i.e., without a chemical separation of the two analytes from each other. Exact emission wavelengths as well as emission spectra of (234)U centered around λ = 411.590 nm and λ = 424.408 nm are reported here for the first time. Emission spectra of the isotopic standard reference material IRMM-199, comprising about one-third each of (233)U, (235)U, and (238)U, confirmed the presence of (234)U in the investigated samples. For the assessment of the (234)U/(238)Pu amount ratio, the emission signals of (234)U and (238)Pu were quantified at λ = 424.408 nm and λ = 402.148 nm, respectively. The age of the investigated samples (range: 26.7-44.4 years) was subsequently calculated using the (234)U/(238)Pu chronometer. HR-ICP-OES results were crossed-validated through sector field inductively coupled plasma mass spectrometry (SF-ICPMS) analysis of the (234)U/(238)Pu amount ratio of all samples applying isotope dilution combined with chromatographic separation of U and Pu. Available information on the assumed ages of the analyzed samples was consistent with the ages obtained via the HR-ICP-OES approach. Being based on a different physical detection principle, HR-ICP-OES provides an alternative strategy to the well-established mass spectrometric approach and thus effectively adds to the quality assurance of (234)U/(238)Pu age dates.
利用商业上的高分辨率电感耦合等离子体发射光谱（HR-ICP-OES）仪器，开发并验证了一种准确测定各种 Pu 材料（Pu 粉、心脏起搏器电池、(242)Cm 热源等）生产年龄的创新分析方法。这项工作的基础是，在所研究的样品中存在的（238）Pu 的α衰变产生了（234）U，并且可以使用 HR-ICP-OES 明确识别母核和子核。受益于仪器的高光谱分辨率（<5 pm）和两种核素发射线的同位素位移，（234）U 和（238）Pu 可以在溶解的样品中被选择性和直接测定，也就是说，无需彼此之间进行两种分析物的化学分离。本文首次报道了（234）U 的精确发射波长以及围绕 λ = 411.590 nm 和 λ = 424.408 nm 的（234）U 发射光谱。包含约三分之一（233）U、（235）U 和（238）U 的同位素标准参考物质 IRMM-199 的发射光谱证实了在所研究的样品中存在（234）U。为了评估（234）U/（238）Pu 量比，分别在 λ = 424.408nm 和 λ = 402.148nm 处对（234）U 和（238）Pu 的发射信号进行了定量。随后，使用（234）U/（238）Pu 计时计计算了所研究样品的年龄（范围：26.7-44.4 年）。通过对所有样品的（234）U/（238）Pu 量比进行同位素稀释，并结合 U 和 Pu 的色谱分离，利用扇形场电感耦合等离子体质谱（SF-ICPMS）分析，对 HR-ICP-OES 结果进行了交叉验证。对分析样品的假定年龄的现有信息与通过 HR-ICP-OES 方法获得的年龄一致。基于不同的物理检测原理，HR-ICP-OES 为建立良好的质谱方法提供了一种替代策略，从而有效地增加了（234）U/（238）Pu 年龄日期的质量保证。
