Isotope Enrichment Using Microchannel Distillation Technology (Final Report) (original) (raw)
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Isotopes isolation Tech part I
The first draft regarding Isotopes isolation and Uranium Enrichment methods, the List of reference ,Figures and Tables will be submitted in the last part insha2allah
Advancement of isotope separation for the production of reference standards
Journal of Radioanalytical and Nuclear Chemistry, 2013
Idaho National Laboratory (INL) operates a mass separator that is currently producing high purity isotopes for use as internal standards for high precision isotope dilution mass spectrometry (IDMS). In 2008, INL began the revival of the vintage 1970s era instrument. Advancements thus far include the successful upgrading and development of system components such as the vacuum system, power supplies, ion-producing components, and beam detection equipment. Progress has been made in the separation and collection of isotopic species including those of Ar, Kr, Xe, Sr, and Ba. Particular focuses on ion source improvements and developments have proven successful with demonstrated output beam currents of over 10 lA 138 Ba and 350 nA 134 Ba from a natural abundance Ba source charge (*2.4 % 134 Ba). In order to increase production and collection of relatively high quantities (mg levels) of pure isotopes, several improvements have been made in ion source designs, source material introduction, and ion detection and collection. These improvements have produced isotopes of high purity ([98 %) and in quantities in the tens of micrograms per run. The instrument and results for pure isotope production for IDMS standards will be presented.
Automated On-Line Isotope Dilution Analysis with ICP-MS Using Sandwich Flow Injection
Analytical Chemistry, 1998
An automated flow injection (FI) manifold is described to perform the addition of isotopic spikes to aqueous samples on-line with ICP-MS for isotope dilution (ID) analysis. The manifold uses the sandwich technique (with the nested loop approach) to perform an injection of the isotopic spike solution within a sample (or standard) plug, the resulting sample-spike-sample sequence being pushed toward the nebulizer by a 1% HNO 3 carrier. A standard, which must contain one element not present in the spike solution to allow the determination of the dispersion coefficient, must also be used to allow a reverse isotope dilution analysis, as well as corrections for mass discrimination and/or spectroscopic interferences. Indeed, because the signals from the individual isotopes are monitored continuously, only one isotope free of spectroscopic interference is required for elements whose isotopic distribution does not vary in nature (two isotopes are still needed for the other elements), as a correction for the interference can be made by comparison with the signals from the standard. Furthermore, this automated approach makes ID-ICP-MS a faster method and does not require any preliminary analysis of the sample because the concentration profile resulting from FI allows the selection of the best isotopic ratio. It was successfully applied to the determination of Mo in saline water.
High-precision continuous-flow isotope ratio mass spectrometry
Mass Spectrometry Reviews, 1997
Although high-precision isotope determinations are routine in 1997), nitrification rates in forests (Starle & Hart, 1997), many areas of natural science, the instrument principles for their biodegradation (Aggarwal et al., 1997), and the climate measurements have remained remarkably unchanged for four history of the earth (Schoell et al., 1994). In ecology and decades. The introduction of continuous-flow techniques to isobiogeochemistry alone, two volumes (Ehleringer & Runtope ratio mass spectrometry (IRMS) instrumentation has predel, 1988; Ehleringer, Hall, & Farquhar, 1993) and at least cipitated a rapid expansion in capabilities for high-precision one meeting (Griffiths, 1996) devoted to applications of measurement of C, N, O, S, and H isotopes in the 1990s. Elemenhigh-precision isotope measurements have appeared in the tal analyzers, based on the flash combustion of solid organic last few years. Isotope ratio MS (IRMS) has penetrated samples, are interfaced to IRMS to facilitate routine C and N areas of biological science to a greater degree than organic isotopic analysis of unprocessed samples. Gas/liquid equilibramass spectrometry. In addition to studies of natural varitors have automated O and H isotopic analysis of water in untreated aqueous fluids as complex as urine. Automated cryo-ability, high-precision isotope measurements facilitate a genic concentrators permit analysis at part-per-million concennumber of tracer techniques in the biomedical sciences, trations in environmental samples. Capillary gas chromatograincluding the doubly labeled water method for energy exphy interfaced to IRMS via on-line microchemistry facilitates penditure (Schoeller et al., 1986), protein turnover studies compound-specific isotope analysis (CSIA) for purified organic (Chapman et al., 1990), fat metabolism (Brenna, 1997), analytes of 1 nmol of C, N, or O. GC-based CSIA for hydrogen and a range of breath tests with the potential to revolutionand liquid chromatography-based interfaces to IRMS have both ize clinical diagnostic testing (Ghoos, Rutgeerts, & van been demonstrated, and continuing progress promises to bring Trappen, 1995). these advances to routine use. Automated position-specific iso-The early history of MS was dominated by physical tope analysis (PSIA) using noncatalytic pyrolysis has been measurements to establish the nominal, terrestrial isotopic shown to produce fragments without appreciable carbon scramabundances of the elements. The early parabola method bling or major isotopic fractionation, and shows great promise for intramolecular isotope ratio analysis. Finally, IRMS notation
On-Line Isotope Dilution Analysis with ICPMS Using Reverse Flow Injection
Analytical Chemistry, 1997
A simple flow injection manifold is described to perform the addition of isotopic spikes to aqueous samples online with ICPMS. The analysis involves one multielement spike injection in the sample carrier and another injection of the spike solution in a standard carrier. This standard must contain one element which is not present in the spike solution, to allow the determination of the dispersion coefficient. The same standard also allows a reverse isotope dilution (ID) analysis, in addition to corrections for mass discrimination and any spectroscopic interference on one of the two isotopes used for the ID analysis. This flow injection approach, therefore, requires only one isotope free of spectroscopic interference for elements whose isotopic distribution does not vary in nature (two isotopes are still needed for other elements since the "natural" ratio must then also be determined). No preliminary analysis of the sample is required prior to the actual ID analysis. Furthermore, the concentration profile resulting from the flow injection allows the selection of the best isotopic ratio in terms of error propagation. This approach, therefore, makes ID analysis as simple as an external calibration but with added accuracy and precision. It was successfully applied to the analysis of a river water certified reference material and to saline water.
Environmental science & technology, 2017
Application of compound-specific stable isotope approaches often involves comparisons of isotope enrichment factors (ε). Experimental determination of ε-values is based on the Rayleigh equation, which relates the change in measured isotope ratios to the decreasing substrate fractions and is valid for closed systems. Even in well-controlled batch experiments, however, this requirement is not necessarily fulfilled, since repetitive sampling can remove a significant fraction of the analyte. For volatile compounds the need for appropriate corrections is most evident, and various methods have been proposed to account for mass removal and for volatilization into the headspace. In this study we use both synthetic and experimental data to demonstrate that the determination of ε-values according to current correction methods is prone to considerable systematic errors even in well-designed experimental setups. Application of inappropriate methods may lead to incorrect and inconsistent ε-value...
Isotopic water separation using AGMD and VEMD
2004
The 18 O isotopic water permeation and separation characteristics of a hydrophobic PTFE membrane using Air Gap Membrane Distillation (AGMD) and Vacuum Enhanced Membrane Distillation (VEMD) were investigated. Permeation fluxes were measured by weighing the collected membrane-permeated water vapor. 18 O/ 16 O of each water sample was analyzed by the Tunable Diode Laser Absorption Spectroscopy (TDLAS). We observed the effects of the air filled membrane pores and the temperature gradient applied to the membrane surfaces on the vapor permeation flux and the oxygen isotope separation for the first time. For both AGMD and VEMD, the permeation flux and the degree of 18 O separation increased as the membrane interfacial temperature gradient increased. Even though, oxygen isotope separation and the permeation flux for VEMD is slightly higher than AGMD, the latter may be more efficient from the system's operational point of view.
Quantitative Imaging of Stable Isotopes by Ion Microprobe
Geostandards and Geoanalytical Research, 2001
In numerous fields of geoscience, e.g. atmospheric, riverine and marine geochemistry or cosmochemistry, isotopic measurements are required at the micrometre scale because of complex mixing of mineral and/or organic particles or because of highly heterogeneous chemical and isotopic distributions. Unfortunately, most mass spectrometers require large amounts of sample (micrograms or milligrams) to perform precise isotopic measurements so that in situ information is difficult to obtain. To overcome these limitations, ion microprobes (SIMS) were developed in the 1960's (Slodzian 1963). These mass spectrometers allow in situ analysis of picogram amounts of material and can record spatial information. Their usefulness in the geosciences has been successfully demonstrated for precise concentration and isotopic determinations (e.g.
System for High Throughput Water Extraction from Soil Material for Stable Isotope Analysis of Water
Journal of Analytical Sciences, Methods and Instrumentation, 2012
A major limitation in the use of stable isotope of water in ecological studies is the time that is required to extract water from soil and plant samples. Using vacuum distillation the extraction time can be less than one hour per sample. Therefore, assembling a distillation system that can process multiple samples simultaneously is advantageous and necessary for ecological or hydrological investigations. Presented here is a vacuum distillation apparatus, having six ports, that can process up to 30 samples per day. The distillation system coupled with the Los Gatos Research DLT-100 Liquid Water Isotope Analyzer is capable of analyzing all of the samples that are generated by vacuum distillation. These two systems allow larger sampling rates making investigations into water movement through an ecological system possible at higher temporal and spatial resolution.