Studies on the voltammetric behaviour of a 2-mercaptoimidazole containing carbon paste electrode: determination of traces of silver

Cai, Xiaohua; Kalcher, Kurt; Neuhold, Christian; Goessler, Walter; Grabec, Irena; Ogorevc, Božidar

doi:10.1007/bf00323695

Cited by 19 publications

(11 citation statements)

References 14 publications

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“…Only Jacobs described simultaneous determination of Ag and Au with a CPE, where mutual interferences could be minimized by proper selection of the accumulation potential [6]. Cai et al observed serious interference from Au"', however, without mentioning its elimination [14]. Therefore, in this work detailed investigations were made to quantify the interfering effect of gold and to find approaches to overcome this problem.…”

Section: Interferences From Metal Ionsmentioning

confidence: 97%

“…The methods based on electrolytic accumulation achieve detection limits as low as 1 x 10-"M [9], however, they often suffer from interferences of other metals that may be preconcentrated simultaneously with silver due to similar reduction potentials (e.g., Cu, Hg or Au). Modified CPEs can circumvent this problem by preconcentrating silver in its monovalent state under open circuit conditions, followed by either a cathodic stripping or by reduction to its elementary state at a fixed potential with subsequent anodic reoxidition [10][11][12][13][14][15][16]. Suitable ligands as modifiers may enhance the selectivity towards the target ions, in case of Agt sulfurcontaining compounds seem to be especially advantageous and were often used [( 10, I I , 13, 14, 161.…”

Section: Introductionmentioning

confidence: 99%

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Voltammetric determination of silver at ultratrace levels using a carbon paste electrode with improved surface characteristics

et al. 1996

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A differential pulse anodic stripping voltammetric method for the determination of silver is described. A new type of electrodeposition for preconcentrating the analyte, Ag+ , was investigated, enhancing the electrolytic accumulation efficiency onto a carbon paste electrode by ion pair formation. A carbon paste electrode containing tricresyl phosphate as a pasting liquid was modified in situ with heptylsulfonic acid (sodium salt). The modifier gave rise to an additional accumulative effect towards the target ions based on ion pairing which resulted in an enhanced sensitivity of the electrode. Additional activation of the electrode surface at -1.0 V (vs. SCE) for 60 s improved the detection limit significantly. The detection limit was found to be 2.5 x M Ag+ (accumulation time 15 min), and could be even lowered by increasing the period of preelectrolysis. The current response was linearly dependent on the concentration up to 2 x 10. M Ag under optimized conditions. The effects of paste composition, voltammetric parameters, composition of the supporting electrolyte as well as the influence of alkylsulfonic acids and of cathodic activation upon the determination of Ag were studied. Interferences from about 20 elements were investigated with particular attention to Cu, Hg, and Au. By masking with ethylenediaminetetraacetate (EDTA), Cu and Hg did not affect the response of Ag up to a 10000-fold and 500-fold molar excess in concentration, respectively. Au did not interfere with the determination of Ag up to a 100-fold molar excess if its absolute concentration w d S lower than 5 x IO-'M. For higher concentration levels, [AuCI4]-could be separated by passing the analyte solution through an anion-exchanger column (Dowex-1) prior to stripping analysis. Due to the extremely low detection limit and high selectivity, the method could be applied to determine Ag at its ubiquitous level in tap water. With this method, the corrosion of silver cutlery in tap water could be monitored. The results agreed well with those obtained by using inductively coupled plasma mass spectrometry (ICP-MS).

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Section: Interferences From Metal Ionsmentioning

confidence: 97%

Section: Introductionmentioning

confidence: 99%

Voltammetric determination of silver at ultratrace levels using a carbon paste electrode with improved surface characteristics

et al. 1996

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“…A number of articles discuss determination of silver(I) by CMEs. The modifiers used include alizarin violet [13], S 2 O 2 -donor dopant [14], vermiculite clay mineral [15], keratin [16], 2,3-dicyano-1,4-naphthoquinone (CYNQ) [17], 2-mercaptoimidazole [18], N,N-diphenyl oxamide [19] and zeolites [20]. Several methods have been used for electrode modification, such as chemisorption, covalent binding, polymer film coating, and composite.…”

Section: Introductionmentioning

confidence: 99%

Langmuir–Blodgett film of p-tert-butylthiacalix[4]arene modified glassy carbon electrode as voltammetric sensor for the determination of Ag+

Wang

Liu

et al. 2009

Journal of Electroanalytical Chemistry

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“…Carbon paste electrodes (CPE) are often used due to their simple modification possibilities [3]. For the determination of Ag + at modified CPE various sulphur containing complexing agents as thiacrowns [4], chelating resins [5], 2,2′-dithiopyridine [6] or 2-mercaptoimidazole [7] have been used as modifiers. Furthermore, silver traces are determined at electrodes modified with quaternized polyvinylpyridine and incorporated metal complexes [8].…”

Section: Introductionmentioning

confidence: 99%

Preconcentration and voltammetric behaviour of Ag + at carbon paste electrodes modified by N-benzoyl-N',N'-di-i-butyl-thiourea

Guttmann

Lubert

Beyer

1996

Analytical and Bioanalytical Chemistry

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The preconcentration of silver at carbon paste electrodes (CPE) modified with N-benzoyl-N',N'-di-i-butyl-thiourea and its subsequent voltammetric determination is studied with test solutions. The preconcentration of silver at the surface of the modified CPE succeeds as well with open circuits as with applied potentials. The amount preconcentrated depends on the electrode potential with a maximum at +0.1 V vs. Ag/AgCl, thus enabling the preconcentration of silver without cathodic treatment. The detection limit is in the order of 10(-4) mmol/l Ag(+). The surface reactions during the preconcentration are discussed. It is assumed that silver complexes of the modifier are formed in a fast reaction followed by a slow reaction with participation of silver and of carbon surface groups.

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Studies on the voltammetric behaviour of a 2-mercaptoimidazole containing carbon paste electrode: determination of traces of silver

Cited by 19 publications

References 14 publications

Voltammetric determination of silver at ultratrace levels using a carbon paste electrode with improved surface characteristics

Voltammetric determination of silver at ultratrace levels using a carbon paste electrode with improved surface characteristics

Langmuir–Blodgett film of p-tert-butylthiacalix[4]arene modified glassy carbon electrode as voltammetric sensor for the determination of Ag+

Preconcentration and voltammetric behaviour of Ag + at carbon paste electrodes modified by N-benzoyl-N',N'-di-i-butyl-thiourea

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