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
Email: schalk@unf.edu
Website: @unf

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Urine

Classification: Biological fluid -> urine -> freeze dried

Citations 5

"Determination Of Copper And Cadmium Using An Online Anodic Stripping Voltammetry Flow Cell With Detection By Inductively Coupled Plasma Mass Spectrometry"
J. Anal. At. Spectrom. 1992 Volume 7, Issue 7 Pages 1131-1137
Jack R. Pretty, Elmo A. Blubaugh, E. Hywel Evans, Joseph A. Caruso and Timothy M. Davidson

Abstract: An online anodic stripping voltammetry flow system was used to deposit copper and cadmium from National Institute of Standards and Technology (NIST) Standard Reference Material (SRM) 2670 Toxic Metals in Freeze-Dried Urine at a working electrode, with release of the analyte for detection by inductively coupled plasma mass spectrometry after the sample matrix was cleared from the cell. Recoveries determined against calibration graphs and by the method of standard additions were 94-115% for copper and 89-97% for cadmium. Spike recoveries for both analytes ranged from 92-106%. Elimination of the sodium-based polyatomic species at m/z = 62 and 63 remains highly efficient for up to 1 x 10^4 µg mL-1 of sodium, whereas the use of dilute nitric acid as electrolyte gives far superior results for copper than those previously reported. Recent improvements in the system manifold design are discussed.
Copper Cadmium Voltammetry Mass spectrometry Electrochemical stripping Preconcentration Reference material Interferences Optimization Flowcell

"Determination Of Cadmium By Flow Injection Isotope-dilution Inductively Coupled Plasma Mass Spectrometry With Vapor-generation Sample Introduction"
J. Anal. At. Spectrom. 1997 Volume 12, Issue 5 Pages 579-584
TARN-JIUN HWANG and SHIUH-JEN JIANG

Abstract: The sample (0.1 ml) is injected into a carrier stream of 2% thiourea/0.0002% Co solution in 0.1 M HCl (4.8 ml/min), which then merges with a stream of 4% NaBH4 solution in 0.1 M NaOH (2.4 ml/min) for passage to a gas-liquid separator that consists essentially of a vessel (diagram presented), containing 120 glass beads (5 mm diameter), from which the Cd-containing vapor is carried to the ICP by a stream of Ar. Interference from MoO+ and ZrO+ is thereby alleviated. Sample-preparation procedures are described for sediments, urine and water, in which 111Cd is added as the tracer; the result is calculated by use of the equation proposed previously (Ibid., 1996, 11, 353). The detection limit is 26 pg/ml of Cd. Recoveries of 5 ng/ml of Cd added to standard refence waters were quantitative, and the results for standard reference freeze-dried urine and marine sediments agreed well with the certified values.
Cadmium Mass spectrometry Mass spectrometry Detection limit Interferences Isotope ratio Reference material Glass beads Volatile generation Volatile generation

"Online Standard Additions With Direct Injection Nebulization For Inductively Coupled Plasma Mass Spectrometry"
Anal. Chem. 1991 Volume 63, Issue 15 Pages 1626-1631
Daniel R. Wiederin, Ronald E. Smyczek, and R. S. Houk

Abstract: A flow injection system is described (with diagram) for online standard additions in trace element determination by the cited technique. Carrier solution is passed through Tefzel tubing (0.5 mm i.d.) to a PEEK tee (0.25 mm i.d.) connected to two high-pressure metal-free flow injection valves via Tefzel tubing. Sample solution are injected via one valve and standard solution are sequentially injected via the second valve. The valves are connected to a second PEEK tee via fused-silica transfer lines (50 µm i.d.). Solutions are passed from the second PEEK tee to the nebulizer through a fused-silica tube. To minimize salt deposition, the direct injection nebulizer tube diameter was reduced to 1 mm, and the tip was modified to accommodate the reduction and the make-up gas flow rate was increased to 0.4 l min-1. The system was applied in the determination of 9 elements in NIST SRM 2670 Toxic Metals in Freeze-Dried Urine. Correction for instrumental drift, viscosity and background effects are discussed.
Trace elements Mass spectrometry Nebulizer Silica Reference material Drift Interferences Standard additions calibration Viscosity

"Determination Of Low Amounts Of Platinum In Environmental And Biological Materials Using Thermospray Nebulization Inductively Coupled Plasma-mass Spectrometry"
Fresenius J. Anal. Chem. 1996 Volume 354, Issue 5-6 Pages 664-667
M. Parent, H. Vanhoe, L. Moens and R. Dams

Abstract: Freeze-dried urine (SRM 2670), plant tissue, and soil or dust (0.1 g) were decomposed with HNO3, HNO3/HClO4 or HNO3/HClO4/HF, respectively. The solutions were heated with aqua regia then HNO3 was removed by evaporation. SnCl2 was added to convert the Pt(IV) to Pt(II). The resulting bis(carboxymethyl)dithiocarbamate complex of Pt(II) was adsorbed on to XAD-4 resin, then back-eluted with ethanol (idem, Biol. Trace Elem. Res., 1994, 43-45, 109). The ethanol was evaporated and the residue was dissolved in 0.5 mL 0.14 M HNO3 containing IR as internal standard. This procedure separated Pt from most matrix elements including Hf. Portions (0.1 ml) were introduced by flow injection into a thermospray nebulizer and the Pt was determined by ICP-MS. Recoveries were variable (from 62-102%) so isotope dilution was carried out with a 194Pt-enriched Pt sponge before the decomposition. The detection limit was 1 pg absolute. The results compared well with those obtained by other methods, e.g., electrothermal AAS or NAA and the certified value.
Platinum Platinum-194 Sample preparation Mass spectrometry Mass spectrometry Reference material Method comparison

"First-order Speciation Of Arsenic Using Flow Injection Hydride-generation Atomic Absorption Spectrometry With In Situ Trapping Of The Arsine In A Graphite Furnace"
Spectrochim. Acta B 1996 Volume 51, Issue 14 Pages 1781-1790
Scott N. Willie

Abstract: Use of the manifold described permits rough 'first-order' speciation in terms of a distinction between combined results for As(III), As(V), methylarsonic acid and dimethylarsinic acid and for these species plus, e.g., arsenobetaine, arsenocholine and tetramethylarsonium, which are unreactive towards NaBH4 and are consequently oxidized by online UV photolysis or off-line microwave heating in the presence of NaOH and K2S2O8 and determined as a group by difference. The method has been applied to biological tissues and aquatic plants (sample preparation described). A non-hydride-forming As fraction has been detected in NIST SRM 2670N urine, and the results for a series of seawater standards have led to the recommendation that the values for As be described as 'hydride-reactive' As.
Arsenic(3+) Arsenic(5+) Arsenoβine Arsenocholine Dimethylarsinic acid monomethylarsonic acid tetramethylarsonium ion Sample preparation Spectrophotometry Speciation Volatile generation Volatile generation Photochemistry UV reactor