针对微量Pu的分析,常用TTA-二甲苯定量萃取稀硝酸中的Pu(Ⅳ),高浓度硝酸反萃,可实现Pu的分离。但反萃液体积较大,采用传统的蒸发法制备α测量源,滴加的解吸液仅为数十μL,导致测量下限较高。采用美国3M公司生产的阴离子固相萃取片,将解吸液中的Pu(Ⅳ)定量吸附于表面,直接烘干制成α测量源后,可在低本底α计数器上测量。操作较为简便,也可大大降低探测下限。本工作研究了样品体积、流速、硝酸浓度等对阴离子固相萃取片吸附Pu(Ⅳ)的影响,并测定了片上吸附Pu的α计数器探测效率。根据研究结果,给出萃取片法制备Pu测量源的推荐流程如下: According to the analysis of trace Pu, the quantitative extraction of Pu (Ⅳ) from dilute nitric acid with TTA-xylene and the stripping of high concentrations of nitric acid can achieve the separation of Pu. However, the stripping solution has a large volume. The traditional method of evaporation was used to prepare the α measurement source. The amount of desorption solution added was only a few tens of μL, resulting in a higher lower limit of measurement. The anion solid phase extraction chip produced by 3M Company in USA was used to quantitatively adsorb Pu (Ⅳ) in the desorption solution to the surface and directly dried to make an α measurement source, which can be measured on a low background α counter. Operation is more simple, but also greatly reduce the detection limit. In this work, the effects of sample volume, flow rate and nitric acid concentration on the adsorption of Pu (Ⅳ) on the anion solid phase extraction chip were studied. The detection efficiency of α-counter adsorbed on the chip was measured. According to the results of the study, the recommended procedure for the extraction of Pu measurement source by the extraction method is as follows: