Determination of plutonium in environmental samples by AMS and alpha spectrometry

Environmental samples from nuclear weapons test sites at the atolls of Mururoa and Fangataufa (French Polynesia, south Pacific) have been analyzed for their content of plutonium isotopes by applying the independent techniques of decay counting (Alpha Spectrometry) and accelerator mass spectrometry (AMS). Here, we propose the combination of both techniques which results in a maximum of information on the isotopic signature of Pu in environmental samples.

Plutonium was chemically separated from the bulk material by anion exchange. ²⁴²Pu was used as an internal standard for both AMS and alpha spectrometry. The samples for alpha spectrometry were prepared by micro-precipitation with NdF₃. After alpha spectrometry, the samples were reprocessed for AMS. Pu was co-precipitated with Fe(OH)₃ and finally, solid samples were prepared. At the VERA (Vienna Environmental Research Accelerator) facility, the various Pu isotopes were separated by their isotopic masses and quantified by the AMS technique.

A good agreement of the results obtained from the AMS measurements was found with those obtained from Alpha Spectrometry. Overall, the data agree on average within 10% of each other. Isotope ratios for ²³⁸Pu, ²³⁹Pu and ²⁴⁰Pu can be extracted from our investigations. Alpha spectrometry delivers data for the ²³⁸Pu and the combination of ^(239+240)Pu concentrations in those samples. In addition, the AMS technique provides information on the individual concentrations of ²⁴⁰Pu and ²³⁹Pu.     

Determination of plutonium isotopes in seawater reference materials using isotope-dilution ICP-MS

We analyzed the activities of (239)Pu, (240)Pu, (239+240)Pu, (241)Pu, the ratio of number of atoms (atom ratio) for (240)Pu/(239)Pu, and the activity ratio of (241)Pu/(239+240)Pu in seawater reference materials, IAEA-443 and IAEA-381, using a highly sensitive isotope dilution sector field inductively coupled plasma mass spectrometry method. With a mean chemical yield of 65% determined with (242)Pu as a tracer, we found that the experimentally established values in IAEA-443 for (239)Pu, (240)Pu, (241)Pu and (239+240)Pu activities are almost the same as those in IAEA-381. Regarding the (239+240)Pu activity, we provided the most precise and accurate result among the twelve laboratories, which participated in the interlaboratory comparison. In addition, for the (240)Pu/(239)Pu atom ratio, our results for IAEA-381 (0.2315±0.0008) and IAEA-443 (0.2325±0.0008) are in good agreement with the IAEA information value (0.229±0.006), but have much smaller uncertainty. Since the new seawater reference material, IAEA-443, is commercially available, it can be used not only for method validation for seawater plutonium isotope ratio and activity analysis, but also for more general use as a plutonium isotope standard for mass discrimination correction for other environmental samples.     

Determination of plutonium isotopes in bilberry using liquid scintillation spectrometry and alpha-particle spectrometry

This paper presents α-particle spectrometry and liquid scintillation spectrometry methods to determine plutonium isotopes in bilberry. The analytical procedure involves sample preparation steps for ashing, digestion of bilberry samples, radiochemical separation of plutonium radioisotopes and their measurement. The validity of the method was checked for coherence using the ζ test, z-test, relative bias and relative uncertainty outlier tests. The results indicated that the recommended procedures for both measurement systems could be successfully applied for the accurate determination of plutonium activities in bilberry samples.     

Determination of plutonium content in high burnup pressurized water reactor fuel samples and its use for isotope correlations for isotopic composition of plutonium

The content of plutonium isotopes in high burnup pressurized water reactor fuel samples was examined using both alpha spectrometry and mass spectrometry after anion exchange separation. The measured values were compared with results calculated by the ORIGEN-2 code. On average, the ratios (m/c) of the measured values (m) over the calculated values (c) were 1.22±0.16 for (238)Pu, 1.02±0.14 for (239)Pu, 1.08±0.06 for (240)Pu, 1.06±0.16 for (241)Pu, and 1.13±0.08 for (242)Pu. Using the Pu data obtained in this work, correlations were derived between the alpha activity ratios of (238)Pu/((239)Pu+(240)Pu), the alpha specific activities of Pu, and the atom % abundances of the Pu isotopes. Using these correlations, the atom % abundances of the plutonium isotopes in the target samples were calculated. These calculated results agreed within a range from 2 to 8% of the experimentally derived values according to the isotopes of plutonium.     

尿钚裂变径迹分析方法与马绍尔居民钚－239内照射剂量的估算

作者介绍了尿钚裂变径迹分析法(简称FTA),剂量评估的现代资料,总结了1981年～1991年中Rongelap和Utirik岛居民钚-239内照剂量估算的结果。目前FTA钚-239的探测水平(99%)为2～3μBq,这相当于马绍尔居民到70岁时,0.2～0.3mSv的有效剂量当量(EDE).大多数样品均低于该探测水平。1991年,由于少数几个高数据,使平均值偏高,因而Rongelap和Utirik岛居民的钚-239平均有效剂量当量估计为0.62和1.6mSv.这是自从1988年以来的最高值。     

尿钚裂变径迹分析方法与马绍尔居民钚－239内照射剂量的估算

作者介绍了尿钚裂变径迹分析法（简称ＦＴＡ），剂量评估的现代资料，总结了１９８１年～１９９１年中Ｒｏｎｇｅｌａｐ和Ｕｔｉｒｉｋ岛居民钚－２３９内照剂量估算的结果。目前ＦＴＡ钚－２３９的探测水平（９９％）为２～３μＢｑ，这相当于马绍尔居民到７０岁时，０．２～０．３ｍＳｖ的有效剂量当量（ＥＤＥ）。大多数样品均低于该探测水平。１９９１年，由于少数几个高数据，使平均值偏高，因而Ｒｏｎｇｅｌａｐ和Ｕｔｉｒｉｋ岛居民的钚－２３９平均有效剂量当量估计为０．６２和１．６ｍＳｖ。这是自从１９８８年以来的最高值。     

二阶导数光谱法测定尿中呋喃妥因浓度

本文采用在酸性条件用乙酸乙酯萃取呋喃妥因后,通过二阶导数光谱法测定尿中呋喃妥因的浓度。该法定量信息为374～377nm处的峰谷之间距离,最低检出浓度为1.5mg/L,回收率为98％,变异系数小于3％,本法与HPLC法进行了对照性研究,两法具有明显的相关性(r=o.9991)。本法可用于呋喃妥因药动学的研究。     

Determination of fluoride in human whole blood and urine by gas chromatography-mass spectrometry

We developed a simple and sensitive method for determination of fluoride in human whole blood and urine using gas chromatography-mass spectrometry (GC-MS). Fluoride was alkylated with pentafluorobenzyl bromide in a mixture of acetone and phosphate buffer (pH 6.8). The derivative obtained was analyzed by GC-MS in the positive-ion electron-impact mode. The lower limit of detection for the compound was 0.5 mg/l for both matrices. The calibration curve for fluoride was linear over the concentration range of 1–100 mg/l. The precision and accuracy of the method were evaluated, and relative standard deviation was within 10%. Using this method, levels of fluoride in whole blood and urine were determined in a case of poisoning caused by hydrofluoric acid exposure.     

Determination of AM-2201 metabolites in urine and comparison with JWH-018 abuse

With respect to the continuous emergence of new synthetic cannabinoids on the market since 2008, evaluation of the metabolism of these compounds and the development of analytical methods for the detection of these drugs including their respective metabolites in biological fluids have become essential. Other than JWH-018 or JWH-073, AM-2201 is one of the frequently identified synthetic cannabinoids in Korea. Recently, in our laboratory, several JWH-018 metabolites have been detected in some urine samples obtained from subjects who were arrested for the possession of herbal mixtures containing only AM-2201 or from those who confessed AM-2201 abuse. In the present study, we identified major urinary metabolites of AM-2201 and several metabolites of JWH-018, i.e., N-5-hydroxylated and carboxylated metabolites from rats administered AM-2201 and found that the metabolic profile in rats was similar to those in human subjects in this study. Analytical results of the urine samples from suspects who had a considerable possibility of AM-2201 or JWH-018 intake were also compared to distinguish between AM-2201 and JWH-018 abuse. The presence of 6-indole hydroxylated metabolites of each drug and N-4-hydroxy metabolite of AM-2201 was found to contribute to the decisive differences in the metabolic patterns of the two drugs. In addition, the concentration ratio of the N-(5-hydroxypentyl) metabolite to the N-(4-hydroxypentyl) metabolite of JWH-018 may be used as a criterion to differentiate between AM-2201 and JWH-018 abuse.     

Determination of plutonium isotopes in freshwater lake sediments by sector-field ICP-MS after separation using ion-exchange chromatography.

The determination of Pu isotopes in lake sediments is important for many studies, such as Pu pollution source identification, sediment mixing estimation, erosion evaluation and establishment of deposition chronology in lakes. In this paper, a simple analytical method using sector field inductively coupled plasma mass spectrometry (ICP-MS) combined with two-stage chromatographic separation and purification of Pu was developed based on the optimization and adaptation of the previously published method for marine samples with an emphasis on the study of the elimination of interferences for the analysis of freshwater lake sediments. A strong base anion-exchange resin (AG MP-1M) was used to purify Pu isotopes with concentrated HBr as the final eluent for Pu elution. The chemical yields were ca. 64% and the decontamination factor for U was ca. 10(5). The developed method was validated using a freshwater lake sediment reference material (SRM-4354) and a marine sediment reference material (IAEA-368), and applied to the determination of Pu isotopes in sediment samples of Lake Poyang, East China. For the analysis of certified reference materials, both 239+240Pu activity of 31.6 mBq g(-1) and 240Pu/239Pu atom ratio of 0.033 for IAEA-368 were comparable to the certified value and/or literature values. As for SRM-4354, 239+240Pu activity of 3.90 mBq g(-1) agreed well with the certified value. However, the mean 240Pu/239Pu atom ratio of 0.144 was lower than those reported by other laboratories. This difference suggested that this material may be isotopically inhomogeneous. 240Pu/239Pu atom ratios of Poyang Lake sediment samples ranged from 0.185 to 0.192 with a mean value of 0.187+/-0.004, indicating that plutonium pollution originated from global fallout.     

湿疹患者血清、皮损和尿液中白三烯以及细胞因子水平的测定

目的:测定湿疹患者血清、皮损和尿液中白三烯(LT)以及细胞因子水平,观察咪唑斯汀对其干预作用,探讨LT在湿疹发病过程中的作用.方法:分别检测20例患者和20名健康志愿者的血、尿以及皮疹中LT含量以及外周血细胞因子的含量,进行统计学分析.结果:湿疹患者外周血IL - 2、IFN - γ水平显著高于正常人对照组,IL - 4水平与正常人对照组无明显差异.湿疹患者外周血LTB4和尿液中LTE4有显著的增高,经咪唑斯汀治疗后,外周血LTB4水平显著降低.湿疹患者外周血INF - γ与LTB4水平呈正相关(r=0.82,P＜0.01).结论:湿疹患者外周血INF - γ与LTB4、外周血LTB4与皮肤组织中LTB4的变化趋势一致.     

硝酸钚致大自鼠骨肉瘤的效应

本文报道了硝酸钚致大白鼠骨肉瘤的实验研究。结果表明,钚确系兵有高度致癌的毒性,在5μCl²³⁹pu/kg组中,大白鼠骨肉宿发生率为38.9%,最早发现骨肉窟的时间为注钚后294天,计算所得每戈瑞的骨肉瘟发生率为0.028。钚诱发大白鼠的骨肉瘤容易扩散到其它脏器。     

Determination of Urine Luck in urine using electrospray ionization tandem mass spectrometry

A simple, rapid and sensitive method using tandem mass spectrometry (MS-MS) has been developed for the determination of chromate Cr⁶⁺ in urine. Cr⁶⁺ is a substantial component of Urine Luck, which is used to conceal the presence of drugs in urine. Cr⁶⁺ was complexed with diethyldithiocarbamate (DDC) and extracted with isoamyl alcohol in the presence of citric acid. Then a 1-μl aliquot of isoamyl alcohol containing Cr-DDC complex was directly injected into an MS-MS instrument without chromatographic separation. The quantification was performed using selected reaction monitoring at m/z 363.8 of product ion CrO(DDC)₂ ⁺ obtained by collision-induced dissociation from the precursor ion, CrOH(DDC)₃ ⁺ at m/z 513.1. This method was validated with the analysis urine samples obtained from volunteers. A linear calibration curve could be obtained in the range of 0.18–100 ng/ml. The limits of detection and quantification of Cr⁶⁺ were 0.05 and 0.18 ng/ml, respectively, using only 10 μl of urine. Results could be obtained in less than 10 min for a sample. After oxidation of Cr³⁺ to Cr⁶⁺, near 100% recovery was confirmed using standard reference materials such as SRM 2670a (low level and high level) and SRM 1643e. The most outstanding advantage of this ESI-MS-MS method is that it gives excellent product ion mass spectra for identification of Cr⁶⁺.     

The biological hazards of plutonium

The health hazards associated with exposure to low levels of plutonium are reviewed since, though the world may escape a nuclear war, there may be virtually permanent contamination of the biosphere by plutonium from a number of sources. It would seem that it is possible to offer workers in the nuclear industry an acceptable level of protection but that low levels of pollution around such sites may build up until there is a hazard for people in the vicinity. The cases of childhood leukaemia found in the vicinity of the Sellafield facility may or may not be related to contamination in the area; however, plutonium is a potent carcinogen, and the foetus seems to be particularly vulnerable to it. The disposal of nuclear waste must be monitored more closely, and it is suggested that the International Atomic Energy Agency should take on this added responsibility.     

Determination of abamectin in heart blood and urine following lethal intoxication: a case report

Forensic Toxicology -     

Targeting of diethylene triamine pentaacetic acid encapsulated in liposomes to rat liver: an effective strategy to prevent bone deposition and increase urine elimination of plutonium in rats

PURPOSE: To modify the distribution of the chelating agent diethylene triamine pentaacetic acid (DTPA) by using a formulation approach with liposomes in order to match the in vivo distribution of plutonium (Pu) and, as a consequence, to improve actinide decorporation. MATERIALS AND METHODS: DTPA was encapsulated in conventional and stealth liposomes. Their pharmacokinetics and ability to remove Pu were evaluated in rats 2 and 16 days after a single intravenous treatment given 2 h after contamination with colloidal Pu (239Pu phytate) or with soluble Pu (238Pu citrate). RESULTS: Both formulations induced major pharmacokinetic modifications in rats, allowing an accumulation of [14C]-DTPA mainly in the liver and secondarily (for stealth liposomes) in bone and spleen. These modifications were associated with major increases in urine elimination and with a decrease in skeletal Pu deposition, depending of the nature of the Pu contaminant. After contamination by Pu phytate, conventional liposomes of DTPA (6 micromol kg(-1)) were as efficient as free DTPA (30 micromol kg(-1)) in maintaining the Pu content in the femur below 4.3% of the injected dose after 16 days, a 3.6-fold reduction compared with free DTPA (4 micromol kg(-1)) treatment or without treatment. CONCLUSIONS: A formulation approach with liposomes appears to be a powerful tool to improve the efficiency of Pu chelating agents in vivo.