Kinetic Phosphorescence Analysis Research Articles

The impact of silver on uranium quantification by kinetic phosphorescence analysis

The impact of silver on uranium quantification by kinetic phosphorescence analysis

Study and measurements of the uranium and amorphous crystals concentrations in urine samples of breast cancer female patients

In this work, Kinetic Phosphorescence Analyzer (KPA) has been used to measure the concentrations of uranium (UC) and Amorphous crystals (AMO) in urine samples of breast cancer patients in Baghdad. Additionally, a relation between UC and AMO with respect to patient's age has been deduced and studied.Forty one urine samples of patients and five for healthy were taken from females lived in different residential area of Baghdad. The measured maximum UC value for urine samples of patients was 2.35 ± 0.053, the minimum value was 0.86 ± 0.034 μg/L, and an overall average was 1.6 ± 0.027 μg/L while the average UC for healthy females was 1.03 ± 0.020 μg/L.From these results, AMO concentrations were found for all breast cancer patients although those patients had not suffered from any kidney function. While all healthy women that tested against uranium and AMO, have been shown zero AMO. Further, UC increases with aging of patients and more incidence of breast cancer of females between the ages 40-59 years. Whereas the value of average AMO independents on the age of patients and also independents on the average value of UC, so the average of AMO is about "+++" for all patients' groups.

Investigating Uranium Concentrations in Groundwaters in the State of Idaho Using Kinetic Phosphorescence Analysis and Inductively Coupled Plasma Mass Spectrometry.

The determination of uranium concentrations in natural water samples is of great interest due to the environmental consequences of this radionuclide. In this study, 380 groundwater samples from various locations within the state of Idaho were analyzed using two different techniques. The first method was Kinetic Phosphorescence Analysis (KPA), which gives the total uranium concentrations in water samples. The second analysis method was inductively coupled plasma mass spectrometry (ICP- MS). This method determines the total uranium concentration as well as the separate isotope concentrations of uranium. The U/U isotopic ratio was also measured for each sample to confirm that there was no depleted or enriched uranium present. The results were compared and mapped separately from each other. The study also found that in some areas of the state, natural uranium concentrations are relatively high.

Oxidative dissolution of unirradiated Mimas MOX fuel (U/Pu oxides) in carbonated water under oxic and anoxic conditions

Few studies exist concerning the alteration of Mimas Mixed-OXide (MOX) fuel, a mixed plutonium and uranium oxide, and data is needed to better understand its behavior under leaching, especially for radioactive waste disposal. In this study, two leaching experiments were conducted on unirradiated MOX fuel with a strong alpha activity (1.3 × 109 Bq.gMOX−1 reproducing the alpha activity of spent MOX fuel with a burnup of 47 GWd·tHM−1 after 60 years of decay), one under air (oxic conditions) for 5 months and the other under argon (anoxic conditions with [O2] < 1 ppm) for one year in carbonated water (10−2 mol L−1). For each experiment, solution samples were taken over time and Eh and pH were monitored. The uranium in solution was assayed using a kinetic phosphorescence analyzer (KPA), plutonium and americium were analyzed by a radiochemical route, and H2O2 generated by the water radiolysis was quantified by chemiluminescence. Surface characterizations were performed before and after leaching using Scanning Electron Microscopy (SEM), Electron Probe Microanalyzer (EPMA) and Raman spectroscopy. Solubility diagrams were calculated to support data discussion. The uranium releases from MOX pellets under both oxic and anoxic conditions were similar, demonstrating the predominant effect of alpha radiolysis on the oxidative dissolution of the pellets. The uranium released was found to be mostly in solution as carbonate species according to modeling, whereas the Am and Pu released were significantly sorbed or precipitated onto the TiO2 reactor. An intermediate fraction of Am (12%) was also present as colloids. SEM and EPMA results indicated a preferential dissolution of the UO2 matrix compared to the Pu-enriched agglomerates, and Raman spectroscopy showed the Pu-enriched agglomerates were slightly oxidized during leaching. Unlike Pu-enriched zones, the UO2 grains were much more sensitive to oxidative dissolution, but the presence of carbonates did not enable observation of an oxidized layer by Raman spectroscopy with the exception of a few areas revealing the presence of U4O9. This data shows the heterogeneous nature of the alteration and the need to combine information from different techniques to determine the origin of releases.

Kinetic phosphorescence analysis to quantify europium and terbium

The ability to accurately quantify europium and terbium may be confounded by the presence of other lanthanides when using spectroscopic techniques such as optical emission spectroscopy, especially at microgram and sub microgram levels. Kinetic phosphorescence analysis (KPA) offers a method to avoid these interferences during measurement of trace levels. This study examined analysis parameters using KPA for europium and terbium by testing the effects of different acids, molarities, and the use of a complexing agent to determine the ideal conditions and limits of detection for each analyte in matrices containing various mixtures of lanthanides.

The matrix influence on the determination of low uranium concentrations by laser induced fluorescence method

A measurement technique enabling the determination of low uranium concentration utilizing system used for time resolved laser induced fluorescence spectroscopy (TRLFS), based on a commercially available kinetic phosphorescence analysis method has been developed. The effect of the matrix, complexing agent, and the level of acidification on the fluorescence spectra and integral intensity was studied. The method is highly influenced by the sample matrix; particularly if different starting uranium salts are in the calibration solutions and in the samples. In the initial study of these effects, TRLFS measurements have been used in order to clarify this behavior.

Preliminary study on the radiological and physicochemical quality of the Umgeni Water catchments and drinking water sources in KwaZulu-Natal, South Africa

Raw and potable water sample sources, from the Umgeni Water catchment areas (rivers, dams, boreholes) in central KwaZulu-Natal (South Africa), were screened for Uranium concentration and alpha and beta radioactivity. Test methods used were gas flow proportional counting for alpha-beta radioactivity, and kinetic phosphorescence analysis (KPA), for Uranium. The uranium levels (median = 0.525 μg/L, range = <0.050–5.010) were well below the international World Health Organization (WHO) (2011) guideline for drinking-water quality (≤15 μg/L). The corresponding alpha and beta radioactivity was ≤0.5 Bq/L (median = 0.084, Interquartile Range (IR) = 0.038, range = 0.018–0.094), and ≤1.0 Bq/L (median = 0.114, IR = 0.096, range = 0.024–0.734), respectively, in compliance with the international WHO limits. For uranium radionuclide, the average dose level, at uranium level of ±0.525 μg/L, was 0.06 μSv/a, which complies with the WHO reference dose level for drinking water (<0.1 mSv/a). There was a distinct trend of cluster of relatively higher Uranium levels of some sources that were found to be associated with the geology/geography and groundwater sources. Overall, the radiological water quality classification, with respect to WHO, is “Blue” – ideal; additional physicochemical analyses indicated good water quality. The analytical test methods employed were found to be suitable for preliminary screening for potential radioactive “hot spots”. The observed Uranium levels, and the alpha/beta radioactivity, indicate contribution largely from Naturally Occurring Radioactive Material (NORM), with no significant health risk to humans, or to the environment.

Determination Uranium Concentrations and Effective Dose of Drinking Water for Nineveh Governorate—Iraq, Using Kinetic Phosphorescence Analyzer (KPA)

In this work, the concentrations of natural Uranium and the annual effective dose (ET in Sv·y-1) in drinking water for Nineveh Governorate in northern Iraq were determined using a pulsed-laser Kinetic Phosphorescence Analyzer (KPA). Furthermore, the relationship between pH for water samples and the concentration of Uranium was studied. The drinking water samples are taken approximately from all regions of Nineveh as; 15 samples of tap water are taken from refinery stations, 13 samples of water samples are taken from wells that are used for drinking, and 18 samples of drinking water are withdrawn from wells in Adayyah region (this region is located near nuclear wastes site). Thus, the total studied samples are 46. The results of Uranium concentration for all samples ranged from 2.61 ± 0.08 to 9.14 ± 0.012 μg·L-1 with an overall average value about 5.87 ± 0.046 μg·L-1, and the total annual effective dose ranged from 2.3 to 8.04 μSv·y-1. The results also showed that the pH number increases with increasing Uranium concentration and have, in general, high values in well water.

Quantitative Analysis of Uranium in Aqueous Solutions Using a Semiconductor Laser-Based Spectroscopic Method

A simple analytical method based on the simultaneous measurement of the luminescence of hexavalent uranium ions (U(VI)) and the Raman scattering of water, was investigated for determining the concentration of U(VI) in aqueous solutions. Both spectra were measured using a cw semiconductor laser beam at a center wavelength of 405 nm. The empirical calibration curve for the quantitative analysis of U(VI) was obtained by measuring the ratio of the luminescence intensity of U(VI) at 519 nm to the Raman scattering intensity of water at 469 nm. The limit of detection (LOD) in the parts per billion range and a dynamic range from the LOD up to several hundred parts per million were achieved. The concentration of uranium in groundwater determined by this method is in good agreement with the results determined by kinetic phosphorescence analysis and inductively coupled plasma mass spectrometry.

Determination of uranium concentration in urine of workers in an Iraqi phosphate mine and fertilizer plants

Precise determination of uranium concentration in human urine is quite important in assessment of occupational and public exposure to uranium. In the present work, a pulsed dye nitrogen laser-induced kinetic phosphorescence analysis (KPA) was used to determine uranium in urine of Iraqi phosphate mine and fertilizer plant workers and in the population living near the mining region. A total of 92 urine samples were collected from workers of the Akashat phosphate mine, the Al-Qaim fertilizer complex, and the Akashat residential region. Uranium concentration in urine of all samples ranged between 0.49 to 5.26 μg L−1 with a total average of 1.47 ± 0.01 μg L−1. For comparison, all samples were also analyzed using a completely different technique; the nuclear fission track analysis using CR-39 SSNTD. Both techniques were capable of such measurements, although not with an equal degree of uncertainty. KPA technique is found to be more suitable for analysis of urine samples having high concentrations of uranium.

Resolution of uranium isotopes with kinetic phosphorescence analysis

This study was conducted to test the ability of the Chemchek™ Kinetic Phosphorescence Analyzer Model KPA-11 with an auto-sampler to resolve the difference in phosphorescent decay rates of several different uranium isotopes, and therefore identify the uranium isotope ratios present in a sample. Kinetic phosphorescence analysis (KPA) is a technique that provides rapid, accurate, and precise determination of uranium concentration in aqueous solutions. Utilizing a pulsed-laser source to excite an aqueous solution of uranium, this technique measures the phosphorescent emission intensity over time to determine the phosphorescence decay profile. The phosphorescence intensity at the onset of decay is proportional to the uranium concentration in the sample. Calibration with uranium standards results in the accurate determination of actual concentration of the sample. Different isotopes of uranium, however, have unique properties which should result in different phosphorescence decay rates seen via KPA. Results show that a KPA is capable of resolving uranium isotopes.

The US Transuranium and Uranium Registries: forty years' experience and new directions in the analysis of actinides in human tissues

Abstract The US Transuranium and Uranium Registries (USTUR) studies the distribution, biokinetics and tissue dosimetry of actinide elements through radiochemical analysis of autopsy tissues voluntarily donated by occupationally exposed persons. The paper provides an overview of the analytical methods for plutonium (Pu), americium (Am) and uranium (U) isotopic determination in human tissues currently applied at USTUR. The results of inter-comparing 239+240Pu, 241Am and 234,235,238U determinations by sector field inductively coupled mass spectrometry (SF-ICP-MS), α-spectrometry (AS) and kinetic phosphorescence analysis (KPA) are discussed. SF-ICP-MS is a major advance over AS and KPA in enabling the measurement of the 240Pu/ 239Pu atom ratio, the short-lived β-emitter 241Pu, and long-lived 236U. For the first time, 241Am and 241Pu were measured in human tissues using SF-ICP-MS. The paper also presents a new avenue of USTUR research in the application of laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) to elemental bio-imaging (EBI) of the actinides in human tissues.

Determination of uranium isotope concentrations in precipitation in the vicinity of lignite-fired power plants

Coal- and lignite-fired power plants produce significant amounts of fly ash, which in many cases contains high concentrations of naturally occurring radionuclides such as 238U. This is of importance from the radio-environmental point of view since a small portion of the fly ash escapes from the power plant filtering system and disperses in the surrounding atmosphere. In addition, coal- and lignite-fired plants related activities such as fuel mining and ash deposition contribute to the suspended matter in the air with particles containing naturally occurring radionuclides. In this study, rainwater samples were collected in the Megalopolis lignite field basin of the Arcadia prefecture in Greece, where lignite-fired power plants are in operation and related activities are fully developed. The samples were preconcentrated and analyzed with alpha spectrometry and kinetic phosphorescence analysis in order to determine the levels of uranium isotope concentrations in precipitation in the Megalopolis basin. A control rainwater sample was also collected in the Athens area to account for reference purposes. Concentrations determined via the two techniques were found to be in statistical agreement. The concentration of 238U in the samples collected at the Megalopolis basin varies from 2.2 ? 0.6 to 90 ? 14 mBq/L, and is 5-40 times higher than the concentration of 238U in the sample collected in Athens. This could be attributed to the operation of the lignite-fired power plants, the fossil fuel mines, and the ash depositories.

반응속도론적 인광 분석기를 이용한 환경 시료 중 우라늄 동위원소 분석에 대한 연구

본 논문에서는 반응속도론적 인광 분석기(Kinetic Phosphorescence Analyzer, KPA)를 이 용하여 환경 시료 중의 우라늄 동위원소 분석에 대한 연구를 기술하였다. 극초단파 산분해 기술을 이용하여 토양 및 유리 재질 시료로부터 우라늄 성분을 추출한 후, UTEVA 수지를 통해서 우라늄 동위원소를 순수하게 분리하였고 KPA로 우라늄 농도를 정량하였다. 우라늄 표준용액을 사용하여 KPA를 이용한 우라늄 측정법에 대한 선형성 및 재현성 실험을 수행하였다. 우라늄 표준용액, 지하수 및 인증 표준시료에 대해 KPA를 사용하여 우라늄 농도를 측정하여 KPA를 이용한 우라늄 분석법에 대한 신뢰도를 검증하였다. In this paper, the study of analysis of uranium isotopes in environmental samples with a kinetic phosphorescence analyzer (KPA) was described. After leaching uranium fraction from soil and glass material with microwave acid digestion technology, uranium isotopes were purified with UTEVA column, and then measured using KPA. Linearity and repeatability tests for measurement of uranium isotopes were carried out in the uranium standard solution with KPA. The reliability for analytical method of uranium with KPA was validated by its application to uranium standard solution, ground water, IAEA and NIST reference samples.

Leaching of UO2 pellets doped with alpha-emitters (238/239Pu) in synthetic deep Callovian-Oxfordian groundwater

The reactivity of a polycrystalline UO2 surface under alpha irradiation in contact with groundwater is investigated, in the hypothesis of direct disposal of spent fuel in a deep geological repository. Two series of plutonium-doped UO2 samples (specific alpha activity of 18 and 385 MBq·g−1UO2) were leached in a synthetic Callovian-Oxfordian deep groundwater under anoxic conditions (Ar/CO2 3000 ppm, 3.5 bar relative pressure) to assess both the impact of alpha radiolysis of water and the complexing capacity of the groundwater ions on the dissolution of UO2. This study follows a prior one performed in pure and carbonated waters. Firstly, technical developments were necessary for the analyses in the groundwater solution because of its high salt concentrations: quantification limits were determined for the measurement of uranium and radiolytic H2O2 traces in this medium. Secondly, given the very high reactivity of these samples in the presence of air and in order to minimize any prior surface oxidation, a strict experimental protocol was followed, based on high-temperature annealing in Ar + 4% H2 with preleaching cycles. Each type of UO2 pellet was then leached under static conditions for 30 days (anoxic conditions, deep groundwater solutions). Results on the evolution of uranium releases are presented. For the lowest alpha activity (18 MBq·g−1UO2), uranium releases in groundwater were below the quantification limit of 2 × 10−8 mol·L−1 with a kinetic phosphorescence analyzer, even after 30 days. However, for higher alpha activity (385 MBq·g−1UO2) the uranium releases begin to exceed the quantification limit after 14 days of leaching and then increase exponentially. This increase is comparable to results previously obtained in carbonated solutions.

Soil Humic Acid Decreases Biological Uranium(VI) Reduction by Shewanella putrefaciens CN32

Biological reduction of uranium(VI) by Shewanella putrefaciens CN32 was investigated in the presence of soil humic acid (SHA). Experiments were performed under resting cell conditions with uranyl acetate as the electron acceptor and sodium lactate as the electron donor in a NaHCO3 or PIPES/NaHCO3 buffer. SHA significantly decreased the final extent of U(VI) bioreduction (100% uranium bioreduced without humics vs. 50% uranium bioreduced with humics). Dissolved (0.2-μm filter) U(VI) was measured by kinetic phosphorescence analysis where samples were kept anoxic during one measurement, and split samples were oxidized and remeasured. The difference between the anoxic and oxidized measurements was operationally defined as “U(IV) < 0.2-μm.” U(IV) <0.2-μm was detected only in samples containing SHA suggesting that soluble U(IV)–SHA complexes were formed or SHA facilitated the transport of UIVO2 (s) nanoparticles through the filter. Identical experiments conducted with nitrate instead of U(VI) showed that SHA interrupted electron transport to nitrate, and may interact similarly with U(VI). These results suggest that humic materials may influence U immobilization by decreasing U(VI) reduction and enhancing the solubility of U(IV).

Comparison of direct kinetic phosphorescence analysis and recovery corrected kinetic phosphorescence analysis for the determination of natural uranium in human tissues

In the analysis of biological samples with sub ng/g uranium concentrations, pre-concentration has been shown to improve the detection limit for the determination of uranium. Recovery corrected kinetic phosphorescence analysis (KPA) combines pre-concentration and separation of uranium by anion-exchange from human tissues dissolved in 6M HCl, with the radiochemical yield determined by alpha-spectrometry, using 232U as a tracer. Total uranium is determined by KPA after correction for chemical recovery. Twenty-one randomly selected dissolved tissue samples from the United States Transuranium and Uranium Registries (USTUR) Case 0242 were chosen for comparative analyses. The set of samples included dissolved bone and soft tissues. Uranium concentrations for seven of the samples had not been previously reported. Direct KPA could not be used to determine uranium concentrations of five unreported tissues. Three of these tissues had uranium concentrations at or below the KPA L Q value of 0.028 ng/ml and two tissues had known matrix interferences. All seven of the unreported tissues were successfully analyzed by recovery corrected KPA; concentrations ranged from 9 to 1380 ng per tissue, including those that could not be analyzed by direct KPA due to matrix problems. Recovery corrected KPA gives results similar to direct KPA where matrix interferences and low detection limits are not encountered. A comparison of the direct method of KPA versus recovery corrected KPA shows marked improvement for the determination of uranium in samples that heretofore either uranium was not detected or the sample had to be drastically diluted to minimize matrix effects in order to measure uranium.

Comparison of direct kinetic phosphorescence analysis and recovery corrected kinetic phosphorescence analysis for the determination of natural uranium in human tissues

Comparison of direct kinetic phosphorescence analysis and recovery corrected kinetic phosphorescence analysis for the determination of natural uranium in human tissues

Setting up and implementation of a global atmospheric radioactivity monitoring network for CTBT verification purposes

Sandia National Laboratories collects bioassay samples to monitor individuals for possible exposure to uranium and thorium as part of ongoing medical surveillance of employees. The current analytical methods involve separation chemistry and alpha-spectrometry for isotopic measurements or kinetic phosphorescence analysis for total uranium. There are several areas where this monitoring can be improved (e.g., analysis times and accurate isotopic ratio measurements). In addition, in case of accidents or exposure to people who are not routinely monitored, the optimum window for collecting bioassay samples may be missed. An example of this scenario is the recent concern over the exposure of civilians to depleted uranium from military ammunition in Kosovo and Kuwait. For these cases, hair may be an alternative bioassay. Analytical procedures utilizing an inductively coupled plasma mass spectrometer (ICP-MS) have been developed that have simplified sample processing and improved the isotopic ratio measurements. The focus of this study is to survey the background levels for 235 U, 236 U, 238 U, and 232 Th isotopes in hair, urine, and drinking water which could be used to determine action levels for follow-up monitoring. In addition, variations of 238 U to 235 U mass ratio for the background samples are measured. The analytical procedures, achieved detection limits, observed background distributions, and the results of uranium isotope ratio tests are presented.

Excretion of depleted uranium by Gulf war veterans

During the Persian Gulf War, in 1991, approximately 100 US military personnel had potential intakes of depleted uranium (DU), including shrapnel wounds. In 1993, the US government initiated a follow-up study of 33 Gulf War veterans who had been exposed to DU, many of whom contained embedded fragments of DU shrapnel in their bodies. The veterans underwent medical evaluation, whole-body counting, and urinalysis for uranium by kinetic phosphorescence analysis (KPA). Data are available from seven individuals who exceeded the detection limit for whole-body counting and also had elevated urinary uranium. Urinary excretion rates, in microg U g(-1) creatinine, were determined in 1997 and 1999. The body contents, in mg DU, were determined in 1997; it is assumed there were no significant decreases in total body content in the interim. For the 1997 data, the mean fractional excretion was (2.4 +/- 2.8) x 10(-5) g(-1) creatinine, and for the 1999 data, the mean was (1.1 +/- 0.6) x 10(-5) g(-1) creatinine. However, these means are not significantly different, nor is there any correlation of excretion rate with body content. Thus, human data available to date do not provide any basis for determining the effects of particle surface area, composition and solubility, and biological processes such as encapsulation, on the excretion rate.