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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Classification: Marine -> shellfish -> lobster

Citations 2

"A Comparison Between ICP-MS And AFS Detection For Arsenic Speciation In Environmental Samples"
Talanta 2000 Volume 51, Issue 2 Pages 257-268
Jose Luis Gómez-Ariza, Daniel Sánchez-Rodas, Inmaculada Giráldez and Emilio Morales

Abstract: Performances of two atomic detectors, Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) arid Atomic Fluorescence Spectrometry (AFS) have been compared for arsenic speciation in environmental samples. Instrumental couplings, based on the use of high performance liquid chromatography (HPLIC), hydride generation (HG), and the two atomic detectors were used for the speciation of arsenite, arsenate, dimethylarsinic acid and monomethylarsonic acid. Optionally, arsenobetaine was also determined using on-line ultraviolet (UV) photooxidation. The detection limits ranging from 0.1 to 0.3 µg L-1 (as As) and the precision > 10% RSD obtained with HPLC-(UV)-HG-AFS were comparable with those obtained with HPLC-(UV)-HG-ICP-MS. Both instrumental coupling were applied to the NRCC-TORT-1 and several environmental samples, such as seawater, freshwater, sediments, bivalves and bird eggs, taken from two areas with different degrees of pollution. No influence of the sample matrix was observed on the results using external calibration and standard additions met:hods, for both coupled techniques.
Arsenate ion Arsenite Arsenoβine Dimethylarsinic acid monomethylarsonic acid Fluorescence Mass spectrometry Sample preparation HPLC Speciation Extraction Method comparison Reference material Interferences Standard additions calibration Optimization

"Determination Of Cadmium In Fertilizers By Flow Injection Spectrophotometry"
Anal. Chim. Acta 1995 Volume 308, Issue 1-3 Pages 439-445
JoséAnchieta Gomes Neto, H. Bergamin, Elias Ayres G. Zagatto* and Francisco J. Krug

Abstract: The flow injection procedure for the determination of Cd in fertilizers was based on the formation of the blue ternary complex between Cd, iodide and Malachite Green (MG). The fertilizer solution was injected into a 0.05 M HNO3 carrier stream (3.2 ml/min) using a 150 cm sampling loop. The stream was successively merged with reagents R1, R2 and a previously mixed stream of reagents R3 and R4. R1 was 0.01 M picolinic acid in 0.6 M sodium acetate/0.1 M acetic acid buffer at 0.4 ml/min. R2 was 200 µg/l Cd in 0.05 M HNO3 at 0.8 ml/min. R3 was 2 M KI in 5 mg/ml ascorbic acid solution at 0.4 ml/min and R4 was 0.5 M MG at 0.4 ml/min. The formed ternary complex was propelled to the detector where the absorbance was measured at 690 nm. The calibration graph for Cd was linear for up to 200 µg/l and the detection limit was 2 µg/l. The RSD (n = 10) for the determination of 93 and 35.3 µg/l of Cd were 1.3 and 4%, respectively. Interfering ions (Hg2+, Ag+, Cu2+ and Pb2+) were removed by inserting a Chelex-100 ion exchange column (5 cm x 3 mm i.d.; 50-100 mesh) into the sample stream. The sampling frequency was 60 samples/h. The results were confirmed by tungsten coil-AAS.
Cadmium Spectrophotometry Chelex Complexation Interferences Method comparison