University of North Florida
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Contact Info

Stuart Chalk, Ph.D.
Department of Chemistry
University of North Florida
Phone: 1-904-620-1938
Fax: 1-904-620-3535
Website: @unf

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Classification: Waste -> radioactive

Citations 5

"Determination Of Zirconium With Xylenol Orange By Flow Injection Spectrophotometry: Application To Eluates From Technetium-99m Generators"
Anal. Commun. 1998 Volume 35, Issue 3 Pages 107-108
Kate Grudpan, Mayuree Utamong and Colin G. Taylor

Abstract: A procedure for the determination of Zr using Xylenol Orange was developed from a conventional spectrophotometric one. An acidic medium of sulfuric acid rather than HClO4 was adopted, to achieve a fast reaction rate and greater sensitivity. Under optimized conditions, calibrations are linear over a range of at least up to 10 ppm of Zr. The detection limit is 0.08 ppm and precisions (RSDs) at the 1, 3 and 5 ppm levels were 2.3, 1.9 and 0.2, respectively. The procedure is free of interferences from species which are present in the eluate from a 99 mTc generator, and was applied to the determination of Zr in such an eluate.
Zirconium Spectrophotometry Optimization

"Automation Of Radiochemical Analysis By Flow Injection Techniques. Americium-plutonium Separation Using TRU-resin Sorbent Extraction Column"
J. Radioanal. Nucl. Chem. 1998 Volume 234, Issue 1-2 Pages 231-235
O. Egorov, J. W. Grate and J. Ruzicka

Abstract: A rapid automated flow injection analysis (FIA) procedure was developed for efficient separation of Am and Pu from each other and from interfering matrix and radionuclide components using a TRU-resin (EIChrom) column. Selective Pu elution is enabled via on-column reduction The separation was developed using online radioactivity detection. After the separation had been developed, fraction collection was used to obtain the separated fractions. In this manner, a FIA instrument functions as an automated separation workstation capable of unattended operation.
Americium Plutonium Ion exchange Radiochemical Preconcentration Resin Interferences On column reduction Automation

"Isotopic And Ultratrace Analysis Of Uranium In Radioactive Waste Samples By Double-focusing Sector Field ICP-MS"
Schr. Forschungszent. Juelich, Reihe Energietech. 1998 Volume 2, Issue 1997 Pages 323-327
Kerl, W.;Becker, J.S.;Dietze, H.J.;Dannecker, W.

Abstract: To optimize the determination of U, ultrasonic nebulization for double-focused sector field ICP-MS was found to be the best nebulization method. With this method the detection limits for several actinide isotopes in highly pure water were determined A precision of <0.1% RDS was achieved for isotopic ratio determination in the ng/mL concentration. range, and the excellent agreement of isotopic ratios obtained by double-focusing sector field ICP-MS and α-spectrometry even for comparable small values of isotopic ratios down to 10^-6 demonstrated the capability of ICP-MS. To minimize the radioactive contamination in the instrument a microconcentric nebulizer in combination with an HPLC injection valve was suitable for flow injection analysis to reduce the sample volume to several µL.
Uranium Mass spectrometry Nebulizer Optimization

"Precise Isotope Ratio Measurements For Uranium, Thorium And Plutonium By Quadrupole-based Inductively Coupled Plasma Mass Spectrometry"
Fresenius J. Anal. Chem. 1999 Volume 364, Issue 5 Pages 482-488
J. S. Becker and Hans-Joachim Dietze

Abstract: Precise long-term measurements of uranium and thorium isotope ratios was carried out in 1 wg/L solutions using a quadrupole inductively coupled plasma mass spectrometer (ICP-QMS). The isotopic ratios of uranium (235U/ 238U = 1, 0.02 and 0.00725) were determined using a cross-flow nebulizer (CFN, at solution uptake rate of 1 mL/min) and a low-flow microconcentric nebulizer (MCN, at solution uptake rate of 0.2 mL/min) over 20 h. For 1 wg/L uranium solution (235U/238U = 1) relative external standard deviations (RESDs) of 0.05% and 0.044% using CFN and MCN, respectively, can be achieved. Additional short term isotope ratio measurements using a direct injection high-efficiency nebulizer (DIHEN) of 1 wg/L uranium solution (235U/238U = 1) at a solution uptake rate of 0.1 mL/min yielded an RSD of 0.06-0.08%. The sensitivity of solution introduction by DIHEN for uranium, thorium and plutonium (145 MHz/ppm, 150 MHz/ppm and 177 MHz/ppm, respectively) increased significantly compared to CFN and MCN and the solution uptake rate can be reduced to 1 wL/ min in DIHEN-ICP-MS. Isotope ratio measurements at an ultralow concentration level (e.g. determination of 240Pu/ 239Pu isotope ratio in a 10 ng/L Pu waste solution) were carried out for the characterization of radioactive waste and environmental samples.
Thorium-232 Uranium Mass spectrometry Mass spectrometry Isotope ratio

"Further Studies On Model Radioactive Wastewaters By Reverse Radiometric Flow Injection Analysis"
J. Radioanal. Nucl. Chem. 1997 Volume 22, Issue 2 Pages 255-257
Myint U, Khin Khin Saw, Nang Mo Kham and J. T&ouml;lgyessy

Abstract: Rapid, safe and cost effective techniques for study of radiochemical wastes have been investigated by many workers. This work deals with a further study on this aspect by reverse radiometric flow injection analysis (rRFIA) technique. 137Cs and 60Co were determined in model radioactive wastewaters.
Cobalt-60 Cesium-137 Radiochemical Reverse