University of North Florida
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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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NIST 1640

Citations 2

"On-line Preconcentration System For Vanadium Determination In Drinking Water Using Flow Injection-inductively Coupled Plasma Atomic Emission Spectrometry"
Anal. Chim. Acta 2000 Volume 420, Issue 1 Pages 73-79
R. G. Wuilloud, J. A. Salonia, J. A. Gásquez, R. A. Olsina and L. D. Martinez

Abstract: An on-line vanadium a pre-concentration and determination system implemented with inductively coupled plasma atomic emission spectrometry (ICP-AES) associated to low flow injection (FI) was studied. For the retention of vanadium, 2- (5-Bromo-2-pyridylazo)-5-diethylaminophenol (5-Br- PADAP) and Amberlite XAD-7 were used, at pH 3.7. The vanadium was removed from the mcirocolumn in countercurrent with nitric acid. An enrichment factor (EF) of 75 was obtained. The detection limit value for the pre-concentration of 50 mL of aqueous solution of vanadium was 0.04 µgl-1. The precision for 10 replicate determinations at the 5 µg L-1 vanadium levels was 2.5% relative standard deviation (R.S.D), calculated with the peak heights obtained. The calibration graph using the pre-concentration system for vanadium was linear with a correlation coefficient of 0.9996 at levels near the detection limited up to at least 50 µgl-1. The method was successfully applied to the determination of vanadium in drinking water samples.
Vanadium Spectrophotometry Preconcentration Extraction Amberlite Reference material Optimization

"Determination Of Arsenic And Selenium In River Water By Hydride-generation Inductively Coupled Plasma Mass Spectrometry With High Resolution"
Anal. Sci. 1996 Volume 12, Issue 4 Pages 623-627

Abstract: A hydride-generation flow injection ICP-MS method for the determination of As and Se in river water is presented. For As, 100 mL water was boiled for 5 min with 1 mL concentrated HNO3, the pH was adjusted to 3.5 and the solution was applied to a Chelex 100 chelating resin. For Se, 100 mL water was boiled for 5 min with 2 mL concentrated HCl and the solution was applied to a chelex resin as above after pH adjustment. Both column eluate were diluted with water until the acidity became 0.1 M. Each sample was transferred in turn to the hydride generation system (schematic shown). Variable speed peristaltic pumps were used to mix sample solutions with 0.2% sodium tetrahydroborate(III) solution (both at 1 mL/min) in a Pyrex mixing coil (15 cm x 2 mm i.d.). The hydrides generated were swept continuously into the ICP torch (operating parameters given) and As and Se were detected by the MS operating at a resolution of 10,000 in selected-ion monitoring mode at m/z 75 and 82, respectively. Using standard solutions, the detection limits were 0.03 and 0.06 ng/ml, respectively, for As and Se. Interference levels of foreign ions on the determination of As and Se are listed. Results (tabulated) obtained the elements in NIST reference materials agreed with certified values. The concentration levels of As and Se in Japanese rivers close to industrial production sites were in the range 1.62-3.77 and 0.07-0.48 ng/mL, respectively.
Arsenic Selenium Mass spectrometry Interferences Reference material Chelex Resin