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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Citations 3

"Determination Of Trace Amounts Of Zinc In Water Samples By Flow Injection Isotope-dilution Inductively Coupled Plasma Mass Spectrometry"
Analyst 1997 Volume 122, Issue 3 Pages 233-237
Tarn-Jiun Hwang and Shiuh-Jen Jiang

Abstract: A water sample (25 ml) was adjusted to pH 4 with 5 mL 1 M ammonium acetate buffer. After a suitable amount of Zn-67 had been added, the solution was diluted to 50 mL with water. A portion (10 ml) of the resulting solution was loaded at a flow rate of 10 ml/min on to a column (5 cm x 10 mm i.d.) of SO3-quinolin-8-ol carboxy-methylcellulose. The column was washed with 0.1 M ammonium acetate buffer of pH 4; the retained Zn was eluted (3 ml/min) with 0.5 M HNO3. The eluate was analyzed by ICP-MS (details given). The Zn-66/Zn-67 isotope ratio was calculated from the peak areas of the flow injection peaks. The calibration graph was linear up to 50 ng/ml Zn-66; the detection limit was 14 pg/ml. RSD was 1.4% (n=7). The method was applied to several water CRM; the results agreed with the certified values.
Zinc-66 Zinc-67 Mass spectrometry Mass spectrometry Column Detection limit Reference material Buffer

"Determination Of Cadmium In Environmental Samples By Hydride Generation With In Situ Concentration And Atomic Absorption Detection"
Analyst 1997 Volume 122, Issue 4 Pages 331-336
Henryk Matusiewicz, Mariusz Kopras and Ralph E. Sturgeon

Abstract: A continuous-flow AAS system for Cd determination is described. A Cd solution acidified with HCl was mixed with 1 µg/ml Co and 0.5% thiourea (and also with 0.01 M didodecyldimethyl-ammonium bromide for reaction with KBH4) and diluted to 1 mL with water. The resulting solution was aspirated at a flow rate of 1 ml/min into a continuous-flow system and merged with a stream of either 2% NaBH4 or 4% KBH4 at a flow rate of 1 ml/min. The mixture was passed through a reaction cell/gas-liquid separator maintained at 50°C and the volatile Cd species evolved were carried by an Ar stream on to the inner wall of a GF for in situ pre-concentration at 200°C. Cd analysis was by ET AAS with atomization at 1800°C for 3 s; detection was at at 228.8 nm. The detection limit was 10 ng/l Cd with KBH4 as reagent. RSD were 10^-14% (n = 10). The method was applied to several environmental and biological CRM. The results obtained agreed with the certified values.
Cadmium Spectrophotometry Heated reaction Volatile generation Reference material Phase separator Preconcentration Volatile generation

"Determination Of Copper, Cadmium, Lead, Bismuth And Selenium(IV) In Sea-water By Electrothermal Vaporization Inductively Coupled Plasma Mass Spectrometry After Online Separation"
J. Anal. At. Spectrom. 1998 Volume 13, Issue 5 Pages 363-369
Dirce Pozebon, Valderi L. Dressler and Adilson J. Curtius

Abstract: A procedure for the determination of Cu, Cd, Pb, Bi and Se(IV) in seawater by electrothermal vaporization inductively coupled plasma mass spectrometry, after online separation using a flow injection system, is proposed. Matrix separation and analyte pre-concentration. was accomplished by retention of the analytes complexed with the ammonium salt of O,O-diethyldithiophosphoric acid on C18 immobilized on silica in a minicolumn coupled directly to the autosampler arm of the vaporizer. The methanol used as eluent was vaporized after being automatically injected into the graphite tube, prior to the vaporization of the analytes. The conditions for the online complexation and separation as well as the vaporizer temperature program were optimized. The recoveries from seawater were 90-110%. The accuracy of the method was tested by the anal. of 2 certified seawaters, CASS-3 and NASS-4, from the National Research Council of Canada. The concentration. of Bi in these seawaters was below the method detection limit. The relative standard deviation was <10% (n=6). The throughput was 22 samples/h and the volume of sample consumed was only 2.3 mL. Tl and As(III) were also separated but their complexation in seawater was not efficient.
Copper Cadmium Lead Bismuth Selenium(IV) Mass spectrometry Ion pair extraction C18 Silica Preconcentration Reference material