Low-temperature radiolysis of organic phosphates studied by electron spin resonance

Haase, Karen; Schulte‐Frohlinde, D.; Kouřím, P.; Vacek, K.

doi:10.1016/0020-7055(73)90060-0

Cited by 27 publications

(12 citation statements)

References 10 publications

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“…4, mean that the lowest critical energy corresponded to the mechanism involving hydrogen or deuterium exchange at C 3 of the butyl chain 8. This conclusion is also confirmed by several thermodynamic calculations of such a radical stability or the increased mobility of the δ or β hydrogens by the phosphate P=O assisted mechanism,28–33 as previously shown in our own studies 7,. 8…”

Section: Discussionsupporting

confidence: 82%

Study of mass spectrometric fragmentations of tributyl phosphate via collision‐induced dissociation

Lesage

Virelizier

Tabet

et al. 2001

Rapid Comm Mass Spectrometry

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Tributyl phosphate (TBP) fragmentation mechanisms were studied by mass spectrometry (MS) and tandem mass spectrometry (MS/MS), using electron impact (EI) or chemical (CI) ionisation of the parent compound and its deuterated analogues. The study of this simple compound is essential for the analysis of complex post-radiolysis mixtures and the identification of particular effects arising from the radiolysis or acid hydrolysis of TBP during nuclear fuel reprocessing. Energy-resolved mass spectrometry (ERMS) and isotopic labelling helped to establish the fragment ion connectivities by distinct identification of the competitive and consecutive mechanisms. An ion-dipole intermediate hypothesis, proposed previously in the case of alkyl phosphates and phosphonates in order to explain the mobility of hydrogen atoms from the alkyl chains, is rejected on the basis of the identification of competitive mechanisms in the TBP fragmentation pathways. Copyright The detailed knowledge of these mechanisms can enable the design of new improved solvent systems, as well as improvements in the reprocessing procedures from the study of these compounds unwanted even at trace levels. In this study, we report an investigation by tandem mass spectrometry (MS/MS) of protonated or deuterated tributyl phosphate and its derivatives, by comparing collisioninduced decomposition (CID) of specifically labelled compounds. In a following paper, we will report CID of protonated (or deuterated) TBP dimers formed by radiolytic degradation, which are important because these compounds are potential complexing agents of plutonium. 6 In a previous paper, 7 the structural identification of isomeric TBP dimers was emphasised as a necessary step to understood their behaviour. All of these results, concerning structural identification of TBP dimers and CID of protonated TBP, allow better investigation of minor functionalised degradation product structures generated by radiolysis, as reported in a previous paper. 8The mass spectrum of TBP obtained under EI conditions includes fragment ions involving consecutive losses of butene together with formation of alkyl carbocations. 14 When studied using a high-pressure CI/NH 3 source, the loss of the alkene chain from TBP 15 or other phosphates can be rationalised by a single H-transfer within the MH ion.Under these conditions, poor intensities of fragment ions are observed because of the low energy deposited on the MH ion. However, the high abundance of MH ions easily allows CID studies of these ions. Leroy has studied the CID fragmentation of protonated phosphonates prepared under ammonia chemical ionisation conditions. 16 These results enabled establishment of the proton affinity scale for some phosphonates using Cooks'

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Section: Discussionsupporting

confidence: 82%

Study of mass spectrometric fragmentations of tributyl phosphate via collision‐induced dissociation

Lesage

Virelizier

Tabet

et al. 2001

Rapid Comm Mass Spectrometry

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“…Jin et al [80] attributed the formation of HDBP under these conditions to a combination of dissociative electron capture and decay of excited TBP molecules, while Haase et al [75] reported that electron-attachment could result in either HDBP, or free hydrogen atoms, and a TBP carbon-centered radical. However, the electron-capture reaction is unlikely to be of consequence in the acidic mixed phase due to the fast Radiation Chemistry of TBP Solvent Extraction 11 reactions shown in Eqs.…”

Section: Degradation Mechanismmentioning

confidence: 99%

“…[81,82] In addition to electron attachment, [75] the TBP radical could be produced by hydrogen atom abstraction [81] by reaction with either the radiolytically produced hydrogen atom or hydroxyl radical, as shown in Eqs. 24 and 25:…”

Section: Degradation Mechanismmentioning

confidence: 99%

Review Article: The Effects of Radiation Chemistry on Solvent Extraction: 1. Conditions in Acidic Solution and a Review of TBP Radiolysis

Mincher

Modolo

Mezyk

2009

Solvent Extraction and Ion Exchange

197

100

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“…The work by Mincher et al [1] as well as the TBP book by Navratil [3] have described most of the processes. Most of the research performed on the degradation of TBP solvents has focused on the identifi cation and measurement of degradation products [4][5][6][7], the degradation mechanisms [8][9][10] and the degradation impact factors, such as diluent [11][12][13], water [14, Infl uence of alpha and gamma radiolysis on Pu retention in the solvent TBP/kerosene 15], nitric acid [16][17][18][19], metal ion [20], atmosphere [21], etc. For example, Bellido et al [13] have suggested that the aromatic diluents can reduce the extent of radiolytic degradation of TBP.…”

Section: Introductionmentioning

confidence: 99%

Influence of alpha and gamma radiolysis on Pu retention in the solvent TBP/kerosene

et al. 2014

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Abstract. In light of the issue of radiolysis of the solvent system in PUREX process, alpha and gamma radiation stability of tributyl phosphate (TBP)/kerosene (OK) have been studied in this paper, in which 238 Pu dissolved in the organic phase and 60 Co are selected as alpha and gamma irradiation sources, respectively. The amount of the degradation products not easily removed after the washing process has been measured by the plutonium retention. The effects of the absorbed dose, the TBP volume fraction, the cumulative absorbed dose and the presence of UO 2 2+ and Zr 4+ on the radiolysis of the solvents have been investigated. The results have indicated that the Pu retention increases with the increase of the absorbed dose after alpha or gamma irradiation, and is larger for the solvent containing less TBP. There is competition between UO 2 2+ and Pu 4+ to complex with the degradation products, and Zr 4+ accelerates the radiolysis of the system.

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Low-temperature radiolysis of organic phosphates studied by electron spin resonance

Cited by 27 publications

References 10 publications

Study of mass spectrometric fragmentations of tributyl phosphate via collision‐induced dissociation

Study of mass spectrometric fragmentations of tributyl phosphate via collision‐induced dissociation

Review Article: The Effects of Radiation Chemistry on Solvent Extraction: 1. Conditions in Acidic Solution and a Review of TBP Radiolysis

Influence of alpha and gamma radiolysis on Pu retention in the solvent TBP/kerosene

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