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Methods Development for Ion Chromatography

Description: Ion chromatography (IC) as developed by Small et. al. in 1975 has become an efficient and reliable analytical technique for simultaneous analysis of multiple ions in solution. The principle requirement prior to use the IC for an analysis is sample preparation; these include sample decomposition, solvent extraction, and trapping in case the target element is in the gas phase, etc. Solvent extractions for fluoride, chloride, sodium, ammonium, and potassium ions which are soluble in soils are described. Sample decompositions include silicate rocks using hydrofluoric acid for the determination of phosphorus; organic pesticides using lithium fusion technique for the determination of halide and cyanide ions are also described. After these sample preparation techniques, the aqueous solutions obtained were analyzed on the ion chromatograph for the analyses of the anions and cations mentioned above. Recovery and reproducibility of each technique is in general quite good and the comparison between the results obtained from the IC method and other instrumentation are given.
Date: May 1986
Creator: Supachai Maketon
Partner: UNT Libraries

Efficiency of a Three Inch Higgins Column

Description: The following report describes the usage of a semi-continuous ion exchange contactor--named the Higgins contactor--fit to operate the Purex process, a process that recovers plutonium and uranium from irradiated natural uranium fuel elements. It is intended to use the contactor in the final purification and concentration stage of the process plutonium streams.
Date: December 20, 1956
Creator: Vaughan, Victor C.; Jansen, George & Bagley, Raymond O.
Partner: UNT Libraries Government Documents Department

Transport Processes in Electrochemically Controlled Ion-Exchange Desalination

Description: From Summary: "The results of such experiments are summarized as follows: 1. Anion-responsive electrodes formed with Kraton, graphite, Norit, and Amberlite CG-4B demineralized well at currents up to 10 milli-amperes; regeneration was efficient up to 8 milliamperes. 2. Satisfactory anion-responsive electrodes containing Amberlite IRA-68 could only be formed when resin was first ground while in the sulfate form; it was required that it be added to the paste mixture (Kraton, Norit, and graphite) in the same form."
Date: March 1969
Creator: Evans, S.; Accomazzo, M. A.; Accomazzo, J. E.; Ladacki, M. & Lossett, K. A.
Partner: UNT Libraries Government Documents Department

Development of an Ion Exchange Process for the Recovery of Vanadium

Description: A process for recovering vanadium from acid leach liquors by ion exchange using either columns or resin-in-pulp has been developed. The process is economically feasible, and operating techniques were developed which made the process practical from an operating standpoint. The theory, chemistry, and characteristics of the vanadium ion exchange process are fully discussed.
Date: July 30, 1954
Creator: McLean, D. C.; Hollis, E. T. & Eisenhauer, R. A.
Partner: UNT Libraries Government Documents Department

Ion Chromatography of Soluble Cr(III) and Cr(VI)

Description: Ion chromatography coupled with a conductivity detector was used to investigate the analysis of Cr(III) and Cr(VI) in aqueous samples. An IC methodology for Cr(III) was developed using a cation column and an eluent containing tartaric acid, ethylenediamine, and acetonitrile at pH 2.9. The detection limit of this method can reach 0.1 ppm level with good precision. Several operational parameters were evaluated during the regular use of the method. Comparison of the IC method with AA method showed good agreement between the two methods. The anion exchange column was used for Cr(VI) determination. The best results were obtained with an eluent containing sodium gluconate, borate buffer, glycerin, and acetonitrile. The retention time for the Cr207 2 - sample was 11 min. and the calibration curve was linear between 1.0 and 100 ppm.
Date: August 1988
Creator: Huang, Julie Shiong-Jiun
Partner: UNT Libraries

Rapid Separation of Heavy Rare-Earth Elements

Description: The U.S. Bureau of Mines investigated the separation of heavy rare-earth elements (REE) in an ion-exchange process. An ion-exchange column consisting of two sections, a loading section and a separation section, provides high levels of REE loading and good REE separation with an expected processing cycle of less than a month, while current ion-exchange technology requires more than 5 months. A different resin is used in each section: sulfonic resin in the loading section and iminodiacetic resin in the separation section. The separation section is further divided into two segments: the first conditioned with NH4 and the second with acid. Erbium is loaded onto both segments of the separation column as a retaining ion. Bands of mixed REE eluting between separated bands of pure REE were recycled directly to the column. Without mixed-band recycle, over 80% of the REE eluted from the column was separated into fractions with 99% purity of each element; with such recycle, the percentage of separated elements can be increased to around 90%.
Date: 1995
Creator: Moore, B. W.; Froisland, L. J. & Petersen, A. E.
Partner: UNT Libraries Government Documents Department

Denitration of Rocky Flats Ion-Exchange Resins: Recommendation of Denitration Processes, October 19, 1995

Description: Resin denitration via anion-exchange is an implementable process that can effectively mitigate the hazards associated with stored resins in which the bulk of the nitrate consists of an "exchangeable nitrate" ionically bound to the cationic sites of the anion-exchange resins. Salicylate has been selected as the exchange anion of choice because of its superior selectivity for the Rocky Flats resins and its unique potential for comprehensive recovery and recycle. This report outlines a single recommended resin denigration procedure that is reasonably independent of the resin composition and the current stored form. This procedure is not optimized but rather seeks to `over-treat' the resins so that a single procedure works for the variety of stored resins. The recommended treatment with sodium salicylate reduces resins by 95-99+% the measured exothermic behavior of the ion-exchange.
Date: December 1, 1998
Creator: Espinoza, Jacob; Barr, Mary & Smith, Wayne
Partner: UNT Libraries Government Documents Department

Investigation into the causes for the loss of resolution in an ion chromatograpy resin

Description: Four mechanisms were considered as possible causes of the loss in resolution for a Dionex CG2 ion chromatography resin: 1) presence of inorganic ions strongly bound to the active sites; 2) absorption of organic species; 3) physical alterations; and 4) chemical alterations. The instrumental analyses used to gather data were ICP, FT-IR, SEM, solid C-13 NMR and IC.
Date: May 1988
Creator: Galindo, Irma C. (Irma Concepcion)
Partner: UNT Libraries

Production Separations of Fission-Product Groups for the Radioisotope Program

Description: Report issued by the Oak Ridge National Laboratory discussing the production separation for the radioisotope program. As stated in the abstract, "a general description is given of five years' experience in routine production of fission products of high concentration and high activity levels for the radioisotope program. Details of construction and production processes are given for two systems which were built on ion-exchange principle" (p. 2). This report includes illustrations, and photographs.
Date: August 13, 1952
Creator: Schallert, P. O.
Partner: UNT Libraries Government Documents Department

A Note on the Use of Ion Exchange Resins for the Purification of Urinary Purines, Kynurenic Acid, and Coproporphyrin: (Preliminary Report)

Description: Abstract: "Preliminary studies are reported on the use of the ion exchange resins for the adsorptions of purines, uracil, nucleotides, kynurenic acid, and coproporphyrin. Adenine and guanine are adsorbed on IR-100 resin from neutral solution and eluted by HCl. Kynurenic acid and coproporphyrin are adsorbed from neutral solution on IR-4 resin and eluted by HCl. Coproporphyrin is strongly adsorbed on IR-100 resin from either acid, alkaline, or neutral solution. Kynurenic acid is poorly adsorbed on IR-100 resin from neutral aqueous solution. The preliminary application of these procedures to the spectro-photometric study of urine is described."
Date: July 1946
Creator: Schwartz, Samuel; Wattenberg, Lee & Zagaria, Ralph
Partner: UNT Libraries Government Documents Department

Two Stage Leaching Tests on Utex Ore

Description: Introduction: The object of this test work was to determine the practicability of a two-stage leach using ion-exchange as the method of uranium concentration.
Date: July 22, 1954
Creator: Stanley, Alan; Eisenhauer, Robert & Richardson, Stanley
Partner: UNT Libraries Government Documents Department

Detector Comparison for Simultaneous Determination of Organic Acids and Inorganic Anions

Description: The research reported here is a study of detector systems to determine those most suited for simultaneous organic acid, inorganic anion determination. Comparisons are made on the basis of detection limits and sensitivities for conductivity, UV/Vis, photoconductivity, and derivative conductivity detection systems. The investigation was made using a constant chromatographic system with the only variable component being the detector system. Eluant optimization conditions for each detector are reported along with tables reporting detection limits and sensitivities for each detector system. Various chromatograms are also shown to provide a visual comparison between detector results.
Date: August 1988
Creator: Pannell, Daniel K. (Daniel Kirk)
Partner: UNT Libraries

Separation of Rubidium from Irradiated Aluminum-Encapsulated Uranium

Description: A procedure was developed for separating rubidium from irradiated aluminum encapsulated uranium. The separations procedure produces a final ultra-high purity rubidium chloride product for subsequent high performance mass spectrometric analysis. The procedure involves first removing most of the macro-components and fission products by strong base anion exchange using, first, concentrated HCl, then oxalic acid media and second, selectively separating rubidium from alkaline-earth ions and other alkali-metal ions, including cesium, using Bio-Rex-40 cation-exchange resin. The resultant rubidium chloride is then put through a final vacuum sublimation step. Ultra-pure reagents and specially clean glassware are used throughout the procedure to minimize contamination by naturally-occurring rubidium.
Date: January 1982
Creator: Horwitz, E. P.; Schmitz, F. J. & Rokop, D. J.
Partner: UNT Libraries Government Documents Department