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Analytica chimica acta 01/1999; 381:207-213. · 4.31 Impact Factor
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ABSTRACT: A method is described for the cathodic stripping potentiometric determination of arsenic on a mercury film electrode in 1 M HCl which contained copper (II) ions. Optimum determination of arsenic in this medium was accomplished with an electrolysis potential of −600 mV vs Ag/AgCl (1 M HCl) and application of a small constant reducing current (−1.5 μA) during the stripping step. As little as 2 μg/l of arsenic can be detected by this method in the presence of 5 mg/l copper (II) ions with an electrolysis time of 30 s. A linear concentration range of 10–200 μg/l was achieved under these conditions. Effective reduction of As(V) to As(III) in water, bovine liver and dogfish muscle samples was accomplished with l-cysteine prior to the CSP determination of arsenic.
Analytica Chimica Acta 01/1999; 381:207-213. · 4.55 Impact Factor
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The Analyst 01/1998; 123:1871-1874. · 4.23 Impact Factor
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The Analyst 01/1998; 123:1871-1874. · 4.23 Impact Factor
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Analytical Letters 01/1997; 30(1):147-161. · 1.02 Impact Factor
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Analytical Letters 01/1997; 30(1):147-161. · 1.02 Impact Factor
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Analytica Chimica Acta 01/1995; 302:225-232. · 4.55 Impact Factor
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ABSTRACT: The use of cathodic stripping potentiometry for the reliable determination of trace and ultra trace concentrations of selenium in environmental and biological samples on a glassy carbon mercury film electrode is described. The optimum conditions for the method include 3 M HCl as supporting electrolyte, an electrolysis potential of −100 mV vs. SCE, a constant reduction current of −20 μA and the decomposition of the samples by dry ashing with magnesium nitrate as an ashing aid. Under these conditions, the detection limit is 0.8 μg/l with an electrolysis time of 5 min or 0.04 μg/l with 60 min deposition. The relative standard deviation for the measurement at this level is 6% (n = 7). The presence of inorganic and organic substances such as lead, copper, cadmium, zinc, CTMAB, LAS, LPC and Triton X-100 caused some suppression of the selenium peak, but these effects were easily circumvented by the use of standard additions method and a UV-irradiation procedure. The UV-irradiation of the digested environmental and biological materials was also effective in reducing the required dry ashing period to 1 h, as well as in improving the sensitivity and accuracy of the method.
Analytica chimica acta 01/1994; · 4.31 Impact Factor
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Analytica Chimica Acta 01/1994; 296:69-76. · 4.55 Impact Factor
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01/1993: pages 161-170;
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ABSTRACT: A method is described for the cathodic stripping potentiometric determination of arsenic on a mercury film electrode in 1 M HCl which contained copper (II) ions. Optimum determination of arsenic in this medium was accomplished with an electrolysis potential of −600 mV vs Ag/AgCl (1 M HCl) and application of a small constant reducing current (−1.5 μA) during the stripping step. As little as 2 μg/l of arsenic can be detected by this method in the presence of 5 mg/l copper (II) ions with an electrolysis time of 30 s. A linear concentration range of 10–200 μg/l was achieved under these conditions. Effective reduction of As(V) to As(III) in water, bovine liver and dogfish muscle samples was accomplished with l-cysteine prior to the CSP determination of arsenic.
Analytica Chimica Acta.
