Influence of gamma irradiation on uranium determination by Arsenazo III in the presence of Fe(II)/Fe(III).
Arsenazo III is a widely used reagent for the concentration measurement of uranium and other actinides in aqueous samples. This study indicates that, for routine aqueous samples, due to the strong complexing ability with Arsenazo III, Fe(III) can significantly decrease the UV-Vis absorbance of the U(VI)-Arsenazo III complex, whereas the influence of Fe(II) on the absorbance is negligible. However, when Fe(II) is present in a gamma-irradiated U(VI) aqueous sample, it can give rise to the Fenton reaction, which produces oxidizing radicals that decompose the subsequently added Arsenazo III, leading to a sharp decrease in the absorbance of the U(VI)-Arsenazo III complex. The decrease in absorbance depends on the iron content and irradiation dose. Furthermore, the oxidizing radicals from the Fenton reaction induced by gamma irradiation can be continually produced. Even if the irradiated solution has been aged for more than one month in the absence of light at room temperature and without the exclusion of oxygen, the reactivity of the radicals did not decrease toward the subsequently added Arsenazo III. This finding demonstrates that the presence of Fe(II) in gamma-irradiated U(VI) aqueous samples can lead to incorrect U(VI) measurement using the Arsenazo III method, and a new method needs to be developed for the quantitative determination of U(VI) in the presence of gamma radiation and ferrous iron.
Beijing National Laboratory for Molecular Sciences, Fundamental Science Laboratory on Radiochemistry & Radiation Chemistry, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China.
Zhong
Z
Zheng
Beijing National Laboratory for Molecular Sciences, Fundamental Science Laboratory on Radiochemistry & Radiation Chemistry, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China.
Mingliang
M
Kang
Beijing National Laboratory for Molecular Sciences, Fundamental Science Laboratory on Radiochemistry & Radiation Chemistry, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China.
Chunli
C
Wang
Beijing National Laboratory for Molecular Sciences, Fundamental Science Laboratory on Radiochemistry & Radiation Chemistry, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China. Electronic address: liucl@pku.edu.cn.
Chunli
C
Liu
SUBATECH, Unité Mixte de Recherche 6457, Ecole des Mines de Nantes, CNRS/IN2P3, Université de Nantes, 4 rue Alfred Kastler, BP 20722, 44307 Nantes cedex 03, France.
Bernd
B
Grambow
AMPHOS21, P. Garcia Ifaria 49-51, Barcelona E-08019, Spain.
Lara
L
Duro
SUBATECH, Unité Mixte de Recherche 6457, Ecole des Mines de Nantes, CNRS/IN2P3, Université de Nantes, 4 rue Alfred Kastler, BP 20722, 44307 Nantes cedex 03, France.
Tomo
T
Suzuki-Muresan
D001150:Arsenazo III / Q000737:chemistry*; D016477:Artifacts; D005290:Ferric Compounds / Q000737:chemistry*; D005296:Ferrous Compounds / Q000737:chemistry*; D005720:Gamma Rays; D006861:Hydrogen Peroxide / Q000737:chemistry; D007501:Iron / Q000737:chemistry; D013058:Mass Spectrometry; D013053:Spectrophotometry / Q000379:methods*; D014501:Uranium / Q000032:analysis* / Q000737:chemistry*; D014867:Water / Q000737:chemistry
C045076:Fenton's reagent; D005290:Ferric Compounds; D005296:Ferrous Compounds; D014867:Water; D001150:Arsenazo III; D014501:Uranium; D006861:Hydrogen Peroxide; D007501:Iron
Arsenazo III; Decomposition; Fe(II)/Fe(III); Fenton reaction; Gamma irradiation; U(VI)