Development of an iridium dissolution method for the evaluation of potential radiological device materials

Hodgson, A. P. J.; Jarvis, Kym E.; Grimes, Robin W.; Marsden, Olivia J.

doi:10.1007/s10967-015-4381-1

Cited by 9 publications

(9 citation statements)

References 16 publications

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“…With more aggressive cleaning solutions such as base bath and aqua regia, the catalytic activity of the liners declines but the reactivity remained above the baseline level in all cases after one cleaning treatment (Table ). These observations are consistent with previous reports that complete dissolution of iridium metal is nontrivial. − …”

Section: Resultssupporting

confidence: 93%

In Situ Generation of Catalytically Relevant Nanoparticles from a Molecular Pincer Iridium Precatalyst during Polyol Deoxygenation

et al. 2020

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Pincer complexes such as ( R POCOP)Ir-based species ( R POCOP = κ 3 -C 6 H 3 -1,3-[OP(R) 2 ] 2 ) are widely used as precatalysts for organic transformations with many mechanistic studies of these transformations based on the assumption that the precatalysts retain their molecular nature under catalytic conditions. We demonstrate that even ( tBu POCOP)IrCO ( tBu POCOP = κ 3 -C 6 H 3 -1,3-[OP(tBu) 2 ] 2 ), a precatalyst valued for its stability, can be susceptible to the formation of nanoparticles at elevated temperatures under the acidic reducing conditions required for polyol deoxygenation and that the nanoparticles formed in situ can contribute to the observed hydrogenation activity. The iridium nanoparticles isolated from reaction mixtures by centrifugation and detected on glass and polytetrafluoroethylene (PTFE) reactor liners exhibit a high degree of aggregation and resist common cleaning protocols.

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Section: Resultssupporting

confidence: 93%

In Situ Generation of Catalytically Relevant Nanoparticles from a Molecular Pincer Iridium Precatalyst during Polyol Deoxygenation

et al. 2020

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“…Previous studies using iridium powder have indicated that the species formed is highly dependent on the level of dissolution occurring; with reddish/brown and orangey/yellow coloured solutions being formed during full and partial sample dissolution, respectively [10]. Raman evaluations showed these solutions to have strong similarities, and it was suggested that when full dissolution did not occur an intermediary species was being formed instead of hexachloroiridate(IV).…”

Section: Resultsmentioning

confidence: 99%

“…The authors have therefore been developing a new method for digesting samples where iridium is the main constituent. Using pressure digestion, and hydrogen peroxide (H 2 O 2 ) as an oxidising agent, this method has been shown to be capable of dissolving iridium powder [10]. …”

Section: Introductionmentioning

confidence: 99%

Advances in the development of a dissolution method for the attribution of iridium source materials

Hodgson

Jarvis

Grimes

et al. 2017

J Radioanal Nucl Chem

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To assist in nuclear forensic investigations, new techniques are required to evaluate radioactive materials that may be discovered outside of regulatory control. Using a recently developed pressure digestion method for iridium powder, assessments have been made of this techniques suitability for undertaking iridium target material evaluations. In addition to determining the reaction conditions necessary for total dissolution, these investigations have provided an insight into the elemental impurities that are present within unirradiated iridium targets that are used in QSA Global radiography sources, and established the speciation of the iridium solutions that are formed during this process.

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“…A third iridium standard solution (Ir-3), w (Ir) = 2035 mg kg –1 , was prepared by dissolution of an appropriate amount of high-purity iridium bromide, IrBr 3 ·4H 2 O ( w = 0.9999 g/g purity, Johnson Matthey, Royston, United Kingdom) in 10% HCl. A fourth iridium standard solution (Ir-4), w (Ir) = 235 mg kg –1 , was prepared by dissolution of metallic iridium powder ( w = 0.999 98 g/g purity, Pure Analytical Laboratories, Sellersville PA, USA) in HNO 3 and H 2 O 2 using an acid digestion vessel (Parr Instrument Company, Moline, Illinois, USA) at 220 °C for 3 days and diluted with water …”

Section: Methodsmentioning

confidence: 99%

Determination of the Isotopic Composition of Iridium Using Multicollector-ICPMS

et al. 2017

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Like many other elements, iridium is lacking a calibrated, SI traceable isotope ratio measurement. In this study, we have undertaken absolute isotope amount ratio measurements of iridium by multicollector inductively coupled plasma mass spectrometry (MC-ICPMS) using a state-of-the-art regression model to correct for the instrumental fractionation (mass bias) of isotope ratios using both NIST SRM 997 isotopic thallium and NIST SRM 989 isotopic rhenium as primary calibrators. The optimized regression mass bias correction model is based on incrementally increasing plasma power and short (10-30 min) measurement sessions. This experimental design allows fast implementation of the regression method which would normally require hours-long measurement sessions when executed under constant plasma power. Measurements of four commercial iridium materials provide a calibrated iridium isotope ratio R = 1.6866(6) which corresponds to isotopic abundance x = 0.372 21(8) and an atomic weight of A(Ir) = 192.217 63(17). In addition, we present data on a new Certified Reference Material from NRC Canada IRIS-1 which fulfills the requirements of a delta zero reference for iridium isotope ratio measurements.

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Development of an iridium dissolution method for the evaluation of potential radiological device materials

Cited by 9 publications

References 16 publications

In Situ Generation of Catalytically Relevant Nanoparticles from a Molecular Pincer Iridium Precatalyst during Polyol Deoxygenation

In Situ Generation of Catalytically Relevant Nanoparticles from a Molecular Pincer Iridium Precatalyst during Polyol Deoxygenation

Advances in the development of a dissolution method for the attribution of iridium source materials

Determination of the Isotopic Composition of Iridium Using Multicollector-ICPMS

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