Direct isotopic analysis of solid uranium particulates on cotton swipes by microextraction-ICP-MS.

Autor: Bradley VC; Chemical Sciences Division, Oak Ridge National Laboratory, USA; Chemistry Department, University of Missouri, Columbia, USA., Spano TL; Nuclear Nonproliferation Division, Oak Ridge National Laboratory, USA., Metzger SC; Chemical Sciences Division, Oak Ridge National Laboratory, USA., Ticknor BW; Chemical Sciences Division, Oak Ridge National Laboratory, USA., Dunlap DR; Chemical Sciences Division, Oak Ridge National Laboratory, USA., Zirakparvar NA; Chemical Sciences Division, Oak Ridge National Laboratory, USA., Roach BD; Chemical Sciences Division, Oak Ridge National Laboratory, USA., Hexel CR; Chemical Sciences Division, Oak Ridge National Laboratory, USA., Manard BT; Chemical Sciences Division, Oak Ridge National Laboratory, USA. Electronic address: manardbt@ornl.gov.
Jazyk: angličtina
Zdroj: Analytica chimica acta [Anal Chim Acta] 2022 May 29; Vol. 1209, pp. 339836. Date of Electronic Publication: 2022 Apr 23.
DOI: 10.1016/j.aca.2022.339836
Abstrakt: Direct isotope ratio analysis of solid uranium particulates on cotton swipes was achieved using a solution-based microextraction technique, coupled to a quadrupole inductively coupled plasma - mass spectrometer (ICP-MS). This microextraction-ICP-MS methodology provides rapid isotopic analysis which could be applicable to nuclear safeguards measurements. Particulates of uranyl nitrate hexahydrate (UO 2 (NO 3 ) 2 ·6H 2 O) and uranyl fluoride (UO 2 F 2 ) ranging from 6 μm to 40 μm in length were transferred to cotton swipes with a particle manipulator. The microextraction probe then delivers a 5% nitric acid (HNO 3 ) solvent onto the swipe surface to extract the uranium species. The extracted sample is then delivered to the ICP-MS for isotopic determination. The majority of uranium signal (∼99% and ∼94% for UO 2 (NO 3 ) 2 ·6H 2 O and UO 2 F 2 , respectively) was detected in the first 15 s extraction, while subsequent extractions on the same location had low or no U signal, suggesting near complete removal of the solid uranium compounds from the swipe surface. Ten samples (for each of the uranium compounds), were analyzed for their isotopic composition. For UO 2 (NO 3 ) 2 ·6H 2 O, the determined isotope ratios resulted in a % relative difference (% RD) from the referenced isotope ratios of 0.97, 1.0, and 7.3% for 234 U/ 238 U, 235 U/ 238 U, and 236 U/ 238 U, respectively. The % RD of the UO 2 F 2 isotope ratios were 1.9 and 0.60% for 234 U/ 238 U and 235 U/ 238 U, respectively. The preliminary limits of detection were determined to be 0.002, 0.4, and 60 pg for 234 U, 235 U and 238 U, respectively This work demonstrates that microextraction ICP-MS is a rapid and sensitive method that could directly determine uranium isotope ratios of UO 2 (NO 3 ) 2 ·6H 2 O and UO 2 F 2 particulates on cotton swipes.
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Databáze: MEDLINE
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