Department of Chemical and Biomolecular Engineering , Clemson University , 127 Earle Hall , Clemson , South Carolina 29634 , United States.
Department of Environmental Engineering and Earth Sciences , Clemson University , 342 Computer Court , Anderson , South Carolina 29625 , United States.
Anal Chem. 2018 Mar 20;90(6):4144-4149. doi: 10.1021/acs.analchem.8b00135. Epub 2018 Feb 28.
This contribution describes a rapid, fieldable alpha spectroscopy sample preparation technique that minimizes consumables and decreases the nuclear forensics timeline. Functional ultrafiltration membranes are presented that selectively concentrate uranium directly from pH 6 groundwater and serve as the alpha spectroscopy substrate. Membranes were prepared by ultraviolet grafting of uranium-selective polymer chains from the membrane surface. Membranes were characterized by Fourier-transform infrared spectroscopy before and after modification to support functionalization. Membrane performance was evaluated using uranium-233 or depleted uranium in both deionized and simulated groundwater at pH 6. Functionalized membranes achieved peak energy resolutions of 31 ± 2 keV and recoveries of 81 ± 4% when prepared directly from pH 6 simulated groundwater. For simulated groundwater spiked with depleted uranium, baseline energy resolution was achieved for both isotopes (uranium-238 and uranium-234). The porous, uranium-selective substrate designs can process liters per hour of uranium-contaminated groundwater using low-pressure (<150 kPa) filtration and a 45 mm diameter membrane filter, leading to a high-throughput, one-step concentration, purification, and sample mounting process.
本研究介绍了一种快速、可现场应用的α谱样品制备技术，该技术最大限度地减少了消耗品的使用并缩短了核取证时间线。本文提出了一种功能超滤膜，该膜可从 pH 值为 6 的地下水直接选择性浓缩铀，并可用作 α 谱分析的基底。通过从膜表面紫外光接枝铀选择性聚合物链来制备膜。用傅里叶变换红外光谱对修饰前后的膜进行了表征，以支持功能化。采用铀-233 或贫铀在 pH 值为 6 的去离子水和模拟地下水中进行了膜性能评估。功能化膜可直接从 pH 值为 6 的模拟地下水中制备，实现了 31 ± 2 keV 的峰值能量分辨率和 81 ± 4%的回收率。对于贫铀污染的模拟地下水，两种同位素（铀-238 和铀-234）均实现了基线能量分辨率。多孔、铀选择性基底设计可使用低压（<150 kPa）过滤和 45 毫米直径的膜过滤器，每小时处理数升含铀污染的地下水，实现高通量、一步浓缩、净化和样品安装过程。
