Determination Of Neptunium Research Articles

Determination of neptunium using high resolution sequential ICP-AES

A procedure was developed for determination of Np using HR Sequential ICP-AES. Mutual interference and background free spectral lines of Np at 295.66, 297.43, 297.49, 302.64 nm were identified. The samples of higher concentration (10–20 µg/mL) of Np had been analyzed. Analytical values of 10–20 µg/mL samples were found to be in good agreement with the expected amounts. The concentration of Np between 2 and 4 μg/mL slightly affected as compared to higher concentration. In U/Pu, Np-295.66, 297.43 nm lines were monitored which showed noticeable enhancement of their intensities. The repetitive analyses showed that the precision was better than 2% RSD.

Determination of neptunium in a reprocessing plant by an on-line solid-phase extraction/electrochemical detection system

In this study, a flow-based electrochemical detection system coupled to a solid-phase extraction column was developed for the determination of neptunium in the presence of Pu(IV). Np(V) in the sample solution was completely oxidized to Np(VI) via electrolysis using a column electrode composed of carbon fibers. The column electrode effluent was then loaded onto a TEVA® column, and subsequently onto a UTEVA® column using 3 mol L−1 HNO3. Pu(IV) was retained on the TEVA column and separated from Np(VI), while Np(VI) was retained on the UTEVA column. Np(VI) was eluted from the UTEVA column with 0.01 mol L−1 HNO3 and then introduced directly into a flow-through electrolysis cell. An electrochemical amperometric method with a working potential of +0.1 V (vs. Ag/AgCl) was used to detect Np(VI). The current produced due to the reduction of Np(VI) was continuously monitored and recorded, and the Np concentration was calculated from the peak area. The relative standard deviation of 10 analyses was 2.4 % for an Np solution (0.50 mg L−1) containing 1.0 μg Np. The detection limit, which was determined to be three times the standard deviation, was 35 μg L−1 (70 ng Np).

Экстракционно-хроматографическое определение нептуния и плутония в рафинатных растворах переработки отработанного ядерного топлива с использованием сорбента, импрегнированного смесью фосфорилподанда кислотного типа и нитрата метилтриоктиламмония

Экстракционно-хроматографическое определение нептуния и плутония в рафинатных растворах переработки отработанного ядерного топлива с использованием сорбента, импрегнированного смесью фосфорилподанда кислотного типа и нитрата метилтриоктиламмония

Determination of neptunium in plutonium materials by ICP-MS

An ICP-MS analytical method as an alternative to the current radiochemical method was developed to analyze trace level 237Np in bulk plutonium materials. In this method, 237Np is determined together with a suite of trace elements during a single analysis using one dissolution solution. Method validation was achieved through precision examination, spike recovery study, detection limit determination, comparison of results with the radiochemical method, and laboratory intercomparison studies on Pu metals. The ICP-MS method significantly reduced the analysis cost, the sample amount, consumption of chemicals and waste generation, as well as the sample turnaround time.

Determination of neptunium in environmental samples by extraction chromatography after valence adjustment

Neptunium(V) ions are unstable in acid media, which limits their extraction on chromatographic resins. We developed a novel analytical method to measure Np by either α-spectrometry or inductively coupled plasma mass spectrometry (ICP-MS) after extraction chromatography as Np(VI). We investigated the reactivity of various oxidizing reagents, and determined the retention capacity of Np(IV, V, and VI) on various extraction chromatographic supports. A simple method using two UTEVA resins was used to rapidly detect Np in soil and sediment samples.

Determination of neptunium in soil by ICP-MS

SummaryA fast and simple method for the determination of237Np in soil is presented. The borate fusion decreases the sample pre-treatment time and a TEVA extraction chromatography separates neptunium from uranium and the interfering matrix components. A comparison of the sensitivities of alpha spectrometry and sector field ICP-MS for determination of237Np is presented.

Determination of 237 Np in marine sediment and seawater

Procedures for determination of neptunium in marine sediment and seawatersamples are described. Iron hydroxide Fe(OH)2 –Fe(OH)3 is used for preliminary pre-concentration of neptunium. Secondly,neptunium Np4+ and Pu3+ are separated by tri-isooctylamine-(TIOA)extraction in 8–10M HCl by redox with SO32–-Fe3+ Neptunium Np4+ and uranium U6+ areseparated by back extraction the Np4+ with 2M HCl. Finally, theneptunium is purified from the uranium and thorium by anion exchange in 8MHNO3 and 12M HCl. The stripping of 6M HCl + NH2 OH HClfurther separates the neptunium Np3+ and uranium. Reduction bySO 32– –Fe3+ appeared to be an efficientway to obtain Np4+ The decontamination factors of the procedureare 4.0. 104 for 232 Th, 5.6 . 104 for uraniumand 1.6 . 104 for plutonium.

Luminescent determination of neptunium and plutonium in the environment

The possibilities of membrane preconcentration of neptunium and plutonium from acidic soil leach have been studied. The elaborated technique involves two steps: liquid extraction of Pu(IV) and Np(IV) by HDEHP from the soil leach and accumulation of these elements by solid supported aqueous membrane with K10P2W17O61 in inner solution. It has been shown that actinide's content in the membrane can be measured by photo-luminescent method.

Determination of Neptunium and Plutonium in the Presence of High Concentrations of Uranium by Ion Chromatography–Inductively Coupled Plasma Mass Spectrometry

Ion chromatography (IC) coupled with ICP-MS was used to separate Np, Pu and U, overcoming the isobaric interferences present when the isotopic composition has to be determined and avoiding the influence of the tail of the 238 U peak on the 237 Np and 239 Pu peaks in samples with a high U content. The optimization of the parameters was carried out with a standard solution containing Np, U and Pu (ratio 1:1:1) at the 100 ng ml -1 concentration level. The precision and accuracy of the method were also evaluated using a sample containing 1 ng ml -1 of Np and Pu and 100 ng ml -1 of U. A 200 µl aliquot of the sample (previously treated with silver oxide in order to obtain the elements in a single oxidation state) was injected and, after passing through the separation column, the effluent was passed directly to the nebulizer. Different mobile phases and oxidizing/reducing agents were tested. The use of a high-capacity cation-exchange column (CS10), silver oxide as oxidizing agent and 40 mm 2,3-diaminopropionic acid monohydronitrate in 0.6 m HNO 3 as eluent in isocratic mode provided good resolution and recovery of the elements studied (96–98%). The precision of the method is 2.7, 1.1 and 1.7% for Np:U, Np:Pu and U:Pu, respectively, for a solution containing Np, Pu and U in a ratio of 1:1:1. Isotope dilution analysis applying IC separation was performed for the determination of Pu. The method of standard additions was used for the determination of Np. The agreement between the IC–ICP-MS results and the calculated values was within 15% for most isotopes.

Determination of neptunium in plutonium and mixed uranium-plutonium samples by isotope dilution gamma-spectrometry with243Am as a spike

A method was developed for isolating neptunium from Pu, U or mixed oxide (MOX) samples and its determination by isotope dilution γ-spectrometry (IDGS) using239Np (243Am) as a spike. Extraction chromatography with trilaurylamine fixed on a SGX-C18 support was used for the isolation of Np. The decontamination factors for U, Pu, Am and Pa vary between 1000–2000 and 100, respectively. The average separation yield of Np is (95±3)%. The amount of243Am required for spiking is about 0.2–0.3 μg. It is recommended to use the pair of γ-rays 86.53 keV (237Np)-106.13 keV (239Np) for the assay of neptunium. A relative uncertainty of 4% or better is achievable in the analysis of plutonium samples, containing 0.4–80 μg neptunium. The detection limit, under the proposed experimental conditions, is about 0.05 μg Np. The results were compared with the results obtained by using high resolution γ-spectrometry (HRGS).

Narrow span coulometric analysis of neptunium

A narrow span (E o ′ ±0.1 V) controlled potential coulometric method has been developed for the determination of neptunium in 1M H2SO4 with a RSD of 0.2%. The main advantage of this method over the existing coulometric methods is that it can tolerate up to a 5-fold excess of plutonium. The method involves carrying out the electrolysis to about 97% and calculating by an iterative computation the formal electrode potential in situ, which is used to calculate the total amount present in the sample. The method consists in oxidation of all the neptunium to Np (VI) by Ce(IV), destruction of excess Ce(IV) and reduction of Np(VI) to Np(V) by NaNO2, destruction of excess nitrite by sulfamic acid followed by coulometric titration of Np(V) to Np(VI).

Determination of neptunium using controlled potential coulometry

A method for controlled potential coulometric determination of neptunium by titration with internally electrolytically generated iron(II) has been developed. The method involves oxidation of Np to Np(VI) by Ce(IV), destruction of excess of Ce(IV) by NaNO2 followed by determination of neptunium by reduction of Np(VI) to Np(IV) by internal generation of Fe(II). The method was employed for various neptunium solution samples and a precision of ±0.25% at 2–5 mg level of neptunium was obtained.

Separation and Determination of Neptunium, Plutonium, and Americium Using Coprecipitation with Barium Sulfate

Article Separation and Determination of Neptunium, Plutonium, and Americium Using Coprecipitation with Barium Sulfate was published on August 1, 1986 in the journal Radiochimica Acta (volume 39, issue 4).

Anwendung der Isotopenverdünnung dei der alphaspektrometrischen und aktivierungsanalytischen Bestimmung von Neptunium-237 im bestrahlten Kernbrennstoff

The determination of neptunium in burnt fuel solution is carried out with the help of neutron activation analysis after separation of 237Np. This method is compared with the alpha spectroscopy. In both methods the recovery was determined 238Np or 239Np as a tracer.

Neutron activation analysis method for the determination of neptunium in sub-microgram quantities in process solutions

A neutron activation analysis method, for the estimation of sub-microgram level237Np present in process solutions of a fuel reprocessing plant is described.

Determination of Neptunium in Uranium-Fission Product Mixtures. Initial Extraction with Methyl Isobutyl Ketone

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTDetermination of Neptunium in Uranium-Fission Product Mixtures. Initial Extraction with Methyl Isobutyl KetoneW. J. Maeck, G. L. Booman, M. C. Elliott, and J. E. ReinCite this: Anal. Chem. 1960, 32, 6, 605–607Publication Date (Print):May 1, 1960Publication History Published online1 May 2002Published inissue 1 May 1960https://doi.org/10.1021/ac60162a008RIGHTS & PERMISSIONSArticle Views52Altmetric-Citations13LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (379 KB) Get e-Alerts Get e-Alerts

各種水溶液試料中のネプツニウム-239の定量法

>All neptunium of (IV), (V), and (VI) states in urine is quantitatively coprecipitated onto basic phosphates of calcium and magnesium which are formed when the sample is treated with sodium hydroxide. The determination of neptunium is studied using this coprecipitation procedure. Neptunium can be concentrated by the coprecipitation from large volumes of aqueous samples such as urine, tap water, and sea water. Separation from other radioactive nuclides which are simultaneously coprecipitated onto the precipitate can be attained by the anion exchange. For urine samples basic phosphates of calcium and magnesium were directly precipitated by adding sodium hydroxide solution. For tap water, phosphoric acid and a small amount of the calcium carrier were added in order to carry down neptunium. In the case of sea water, phosphoric acid was added and a small portion of calcium and magnesium phosphates were precipitated by adding a small amount of sodium hydroxide. The precipitate was dissolved with nitric acid. The resultant solution contained 7.5N nitric acid, 0.1M semi-carbazide, and 0.01M ferrous sulfamate. The solution was passed through 1.00 g of Dowex 1 x 8 resin column and washed with the nitric acid-reductant solution, then eluted the adsorbed neptunium with a small amount of 0.2Nmore » nitric acid 0.005M ceric sulfate solution. The recoveries of Np/sup 239/ were 97.0 2.6% for 300 ml of human urine, 97.9 3.1% for 1000 ml of tap water, and 96.4 2.2% for 1000 ml of sea water, respectively. (auth)« less

Separation and Determination of Neptunium by Liquid-Liquid Extraction

Separation and Determination of Neptunium by Liquid-Liquid Extraction