Sequential Injection Approach for Simultaneous Determination of Ultratrace Plutonium and Neptunium in Urine with Accelerator Mass Spectrometry

Abstract

An analytical method was developed for simultaneous determination of ultratrace level plutonium (Pu) and neptunium (Np) using iron hydroxide coprecipitation in combination with automated sequential injection extraction chromatography separation and accelerator mass spectrometry (AMS) measurement. Several experimental parameters affecting the analytical performance were investigated and compared including sample preboiling operation, aging time, amount of coprecipitating reagent, reagent for pH adjustment, sedimentation time, and organic matter decomposition approach. The overall analytical results show that preboiling and aging are important for obtaining high chemical yields for both Pu and Np, which is possibly related to the aggregation and adsorption behavior of organic substances contained in urine. Although the optimal condition for Np and Pu simultaneous determination requires 5-day aging time, an immediate coprecipitation without preboiling and aging could also provide fairly satisfactory chemical yields for both Np and Pu (50-60%) with high sample throughput (4 h/sample). Within the developed method, (242)Pu was exploited as chemical yield tracer for both Pu and Np isotopes. (242)Pu was also used as a spike in the AMS measurement for quantification of (239)Pu and (237)Np concentrations. The results show that, under the optimal experimental condition, the chemical yields of (237)Np and (242)Pu are nearly identical, indicating the high feasibility of (242)Pu as a nonisotopic tracer for (237)Np determination in real urine samples. The analytical method was validated by analysis of a number of urine samples spiked with different levels of (237)Np and (239)Pu. The measured values of (237)Np and (239)Pu by AMS exhibit good agreement (R(2) ≥ 0.955) with the spiked ones confirming the reliability of the proposed method.

Accelerator Mass Spectrometry of Actinides in Ground- and Seawater: An Innovative Method Allowing for the Simultaneous Analysis of U, Np, Pu, Am, and Cm Isotopes below ppq Levels

“…The evaporation continued until almost dryness. Since high levels of organic carbon may interfere with the Fe(OH) 3 coprecipitation, 13 a complete digestion of the sample was performed. Therefore, the sample was transferred to a PFA vessel suited to a MLS GmbH Start microwave oven and digested with 5 mL of conc.…”

Distribution and source of Pu in the sediments of the seas and estuaries of China—a review

“…Subsequently, acid leaching (with 20 mL HNO 3 ) was performed on a hot plate for at least 4 h at 60°C. After this sequence of operations, a two-stage anion exchange chromatography method using AG 1-X8 and AG MP-1 M resins was used for separation and purification of the Pu isotopes (Qiao et al 2013). The final sample solutions were diluted to 1 mL using 4% HNO 3 for Pu analysis.…”

Dynamic Flow Approaches for Automated Radiochemical Analysis in Environmental, Nuclear and Medical Applications

“…SI approaches coupling SPEC or IEC for processing nine samples in a sequential mode showed high sample throughput for 239 Pu, 240 Pu and 237 Np environmental and biological assays [55,57,59,92]. The LOV concept, introduced in 2000, allied to SIA, has emerged as an appealing downscaled analytical tool and provided more possibilities to renew the separation column in a flow system [17,18].…”

“…SI approaches coupling SPEC or IEC for processing nine samples in a sequential mode showed high sample throughput for 239 Pu, 240 Pu and 237 Np environmental and biological assays [55,57,59,92]. Multi-Sample Chromatographic Separation SI approaches coupling SPEC or IEC for processing nine samples in a sequential mode showed high sample throughput for 239 Pu, 240 Pu and 237 Np environmental and biological assays [55,57,59,92]. The system (Figure 9) consists of one syringe pump as the fluid driver and five 10-port selection valves to integrate nine chromatographic columns (TEVA or AG 1 resin).…”

“…The application of automation is important for Figure 9. Schematic deposition of a flow system for four sample simultaneous processes [92]. SV: selection valve.…”