Isotopic determination of trace-level Pu in water requires time-consuming concentration and sample preparation steps, and the samples routinely must be prepared off-site from the contamination source. An analytical method that combines on-site Pu concentration with spectroscopic screening would be a valuable tool for environmental monitoring and nuclear forensics. This contribution describes the development of extractive polymer thin-film composite (e-TFC) membranes for the rapid concentration and isotopic determination of Pu from water. The e-TFC membranes were prepared by spin coating Pu-extractive copolymers on the surface of an ultrafiltration membrane. The copolymers were synthesized from methyl methacrylate or 4-methylstyrene and a Pu-reactive monomer. Three Pu-reactive monomers were evaluated for their ability to create copolymers that were suitable for casting and capable of extracting Pu from water at trace levels. Copolymers containing 5% (w/w) ethylene glycol methacrylate phosphate (EGMP) had distribution coefficients of 92.7 ± 18.5 L/kg for ²⁴²Pu at pH 6.8. e-TFC membranes prepared with an EGMP-based copolymer active layer were effective for concentrating ²⁴²Pu from a 4.53 Bq/mL (1.26 × 10⁻⁸ M) solution at pH 6.8. The resulting alpha spectra of Pu-loaded e-TFC membranes achieved energy resolutions (full-width at half-maximum, FWHM) of 71.7 ± 8.7 keV, allowing for the isotopic discrimination of ²⁴²Pu from ²³⁸Pu/²⁴¹Am also present in the solution.

水中痕量 Pu 的同位素测定需要耗时的浓缩和样品制备步骤，而且样品通常必须在污染源的异地制备。将现场 Pu 浓度与光谱筛选相结合的分析方法将成为环境监测和核法证学的宝贵工具。这一贡献描述了提取聚合物薄膜复合 (e-TFC) 膜的开发，用于从水中快速浓缩和同位素测定。e-TFC 膜是通过在超滤膜表面旋涂 Pu 萃取共聚物制备的。该共聚物是由甲基丙烯酸甲酯或 4-甲基苯乙烯和 Pu 反应性单体合成的。评估了三种 Pu 反应性单体制造适用于浇铸和能够从水中提取痕量 Pu 的共聚物的能力。含5%（w /w) 甲基丙烯酸乙二醇酯磷酸酯 (EGMP) 的分配系数为 92.7 ± 18.5 L/kg，²⁴² Pu 在 pH 6.8 时。用基于 EGMP 的共聚物活性层制备的 e-TFC 膜可有效地从 pH 6.8的 4.53 Bq/mL (1.26 × 10 ^-8 M) 溶液中浓缩²⁴² Pu 。由此产生的载有 Pu 的 e-TFC 膜的 α 光谱实现了 71.7 ± 8.7 keV 的能量分辨率（半高全宽，FWHM），允许从²³⁸ Pu/ ²⁴¹ Am 中区分²⁴² Pu也存在于解决方案。