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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Loam

Classification: Environmental -> soil -> loam

Citations 2

"Determination Of Cadmium, Copper And Lead In Environmental Samples. An Evaluation Of Flow Injection Online Sorbent Extraction For Flame Atomic Absorption Spectrometry"
Anal. Chim. Acta 1994 Volume 285, Issue 1 Pages 33-43
Renli Ma, Willy Van Mol and Freddy Adams*

Abstract: Lake, estuarine or river sediment, calcareous loam soil or coal fly ash were digested in a PTFE bomb with concentrated HF and HNO3 by heating until fuming. After cooling HClO4 was added, the bomb was sealed and heated for 8 h at 150°C. Silicates were removed by repeated addition of HF and HNO3 and evaporation to dryness and the residue was dissolved in HNO3, HCl and water. The solution was injected into a FIA system and mixed with 0.2% ammonium diethyldithiophosphate in 0.1 M citric acid adjusted to pH 1 with HNO3. Following pH dependent complexion with 0.1% diethylammonium-NN-diethyldithiocarbamate in 0.1 M acetic acid (described), 50 mM citric acid was added to mask Fe(III) and Mn(II). The complexes were sorbed onto C18 bonded silica gel (40-63 µm) in a conical extraction column, eluted with methanol and analyzed by AAS; elution rates and AAS nebulizer uptake rates are discussed. Calibration graphs of peak height were linear up to 50 µg/l of Cd, 300 µg/l of Cu and 1 mg/l of Pb with detection limits of 0.8, 1.4 and 10 µg/l, respectively, with a 20 s sample loading at 8.7 ml/min.
Cadmium Copper Lead Sample preparation Spectrophotometry Sample preparation Silica gel C18 Precipitation Solid phase extraction

"Analytical Characteristics Of An Inductively Coupled Plasma Mass Spectrometer Coupled With A Thermospray Nebulization System"
J. Anal. At. Spectrom. 1995 Volume 10, Issue 9 Pages 575-581
Hans Vanhoe, Steven Saverwijns, Magali Parent, Luc Moens and Richard Dams

Abstract: The effects of different matrix salts and mineral acids on analyte ion signals in ICP-MS was evaluated using the thermospray (TS) sample introduction system of Vanhoe et al. (Ibid., 1994, 99, 815). The results were compared with two other sample introduction systems, the pneumatic nebulizer coupled with a spray chamber (the conventional arrangement; CA) and the same nebulizer coupled with the desolvating unit employed with the thermospray nebulizer. Studies were effected with a 10 µg/l multi-element solution of Be, Al, Sc, Co, In, Gd, Tl, Th and U in 0.14 M HNO3 containing 1-5000 mg/l of the matrix elements Na, Ca, P and S (ICP-MS operating conditions tabulated). Non-spectroscopic interferences from Na and Ca were more pronounced for the TS system than the CA but were almost the same for P and S. The TS system was used for the analysis of Cd and Pb in three environmental reference materials (Community Bureau of Reference (BCR) Certified Reference Materials 141R Soil- calcareous loam, 144R sewage sludge-domestic and 146R sewage sludge-industrial, following digestion with aqua regia (experimental details given). A sample flow injection system was used to eliminate memory effects. Results obtained with the TS system agreed more closely with certified values than those obtained with the CA system.
Cadmium Lead Mass spectrometry Sample preparation Reference material Method comparison Interferences