US EPA

4836312 

Journal Article 

Determination of zirconium isotope composition and concentration for nuclear sample analysis using Thermal Ionization Mass Spectrometry 

Quemet, A; Maillard, C; Ruas, A 

2015 

Yes 

International Journal of Mass Spectrometry
ISSN: 1387-3806 

392 

34-40 

10.1016/j.ijms.2015.08.023 

WOS:000366441700006 

A new Thermal Ionization Mass Spectrometry (TIMS) analytical procedure was developed to measure with high accuracy the zirconium isotope abundance and concentration without molybdenum correction in nuclear samples. A zirconium selective separation using UTEVA column was used before the TIMS measurement in order to remove all possible isobaric interferences (Mo, Y, Nb and Ru) in the solution. The separated solution was then deposited onto a filament previously outgassed for 4 h to reduce the molybdenum traces in the filament. Then, the filament was introduced into the TIMS source and was maintained for 4h at a current of 5 A (ionization filament) and 1.2 A (evaporation filament) in order to eliminate all molybdenum trace present in the filament and in the sample. This methodology allowed the zirconium isotope abundance determination without using the molybdenum interference correction equation. The analytical results obtained with a natural solution after separation is in good accordance with the reference values: bias lower than 0.16% for the Zr-90, Zr-91, Zr-92 and Zr-94 isotope abundance, and a bias of similar to 0.8% for the minor isotope (Zr-96) were observed. This zirconium abundance determination methodology was used on three nuclear samples. Then, the calibration of a Zr-91 spike solution was performed by reverse isotope dilution using a SPEX standard zirconium solution. The zirconium concentration determination was then performed on the three nuclear samples by isotope dilution using the SPEX standard zirconium solution and the Zr-91 spike solution. The final uncertainties were estimated to be lower than 1%. (C) 2015 Elsevier B.V. All rights reserved. 

TIMS; Zirconium; Isotope ratio; Isotope dilution; Separation