Cathodic stripping voltammetry of thiosulphate at toxic concentrations

Krista, Jan; Kopanica, M.; Novotný, Ladislav

doi:10.1016/s0003-2670(99)00021-5

Cited by 6 publications

(2 citation statements)

References 16 publications

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“…In this sense, a separation and preconcentration step is necessary especially for UV-Vis spectrophotometry with low sensitivity, in which the thiosulfate levels of samples are lower than detection limit of spectrophotometry as detection tool. In order to determine low contents of thiosulfate of real samples, the traditional separation and preconcentration procedures such as SPE [17], sweeping, which is based on in-line and online preconcentration of neutral and charge analytes in capillary and/or microchips or which is based on partition of the analytes between pseudo-stationary phase and the surrounding phase what promotes separation of analytes from matrix in MEKC [18,19], solvent extraction [20], electrosorption before detection by cathodic stripping differential pulse voltammetry (CS-DPV) at pH 4.4 [21], electrochemical accumulation on a miniaturized modified mercury drop electrode before detection by cathodic stripping voltammetry (CSV) [22], electrochemical deposition before detection by linear sweeping voltammetry (LSV) in a study, which is based on anodic depolarization reaction between sulfur and the mercury electrode at pH 8.3 [23] as well as column-switching separation/preconcentration before analysis by suppressed IC [24] have been used. But these preconcentration procedures have generally limitations such as time-consuming and cumbersome to perform, utility of columns with a narrow internal diameter limiting the flow rates to a range of 1-10 mL min −1 , so as to large trace-enrichment time for large sample volumes, plugging the cartridge of samples with particulate matter, unsatisfactory enrichment factors, using toxic organic solvents, forming secondary waste for extraction.…”

Section: Introductionmentioning

confidence: 99%

Extraction, preconcentration and spectrophotometric determination of trace levels of thiosulfate in environmental waters

Gürkan

Altunay

Gürkan³

2017

J IRAN CHEM SOC

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are statistically in a good agreement with those obtained by DTNB method. Finally, the method developed was successfully applied to the preconcentration and determination of trace thiosulfate from environmental waters. Abstract In the existing study, a new vortex-assisted cloud point extraction (VA-CPE) method was developed for determination of low levels of thiosulfate in environmental waters at 632 nm by spectrophotometry. The method is selectively based on charge-transfer-sensitive ion-pair complex formation of Ag(S 2 O 3 ) 2 3− , which is produced by the reaction of thiosulfate with excess Ag + ions with toluidine blue (3-amino-7-dimethylamino-2-methylphenazathionium chloride, TB + ) and then its extraction into micellar phase of polyethylene glycol 4-tert-octylphenyl ether (Triton X-45) in presence of Na 2 SO 4 as salting-out agent at pH 7.0. All the factors affecting complex formation and VA-CPE efficiency were optimized in detail. Under the optimized conditions, the linear calibration curves for thiosulfate were in the range of 0.2-120 and 5-180 µg L −1 with sensitivity improvement of 81-folds and 15-folds, respectively, as a result of efficient mass transfer obtained by CPE with and without vortex, while it changed in the range of 260-3600 µg L −1 without preconcentration at 642 nm. The limits of detection and quantification of the method for VA-CPE were found to be 0.05 and 0.22 µg L −1 , respectively. The precision (expressed as the percent relative standard deviation) was in range of 2.5-4.8% (5, 10 and 25 µg L −1 , n: 5). The method accuracy was validated by comparing the results to those of an independent 5,5′-dithiobis(2-aminobenzoic acid) (DTNB) method as well as recovery studies from spiked samples. It has been observed that the results * Ramazan Gürkan Keywords

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Section: Introductionmentioning

confidence: 99%

Extraction, preconcentration and spectrophotometric determination of trace levels of thiosulfate in environmental waters

Gürkan

Altunay

Gürkan³

2017

J IRAN CHEM SOC

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“…The determination of thiosulfate has also been made through kinetic measurements based on costly equipment, such as stopped-flow [30] and cathodic-stripping voltammetry [31].…”

Section: Introductionmentioning

confidence: 99%

Kinetic determination of trace amounts of thiosulfate based on its inhibitory effect

Tiwari

Naik

Singh

et al. 2009

JICS

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The sulfur containing ligand viz., thiosulfate is found to inhibit the Ag(I) catalyzed substitution of cyanide in hexacyanoferrate(II) by phenylhydrazine. The inhibitory effect of thiosulfate is attributed due to its tendency to form complexes with Ag(I), leading to the production of inhibitor-catalyst complexes. The reactions, followed spectrophotometrically in aqueous medium at 488 nm, was possible by the increase in absorbance of the cherry-red product, [Fe(CN) 5 PhNHNH 2 ] 3-at pH 2.8 (±0.02), at 30 (±0.1) °C, and an ionic strength (μ) of 0.02 M (KNO 3 ). The linear calibration curves were obtained using the absorbance measured at different times (A t ) and thiosulfate concentrations under specified conditions. The calculated detection limit was 4.9 × 10 -7 M. The Michaelis-Menten constant (K m ) and equilibrium constants for the formation of complexes between catalyst and inhibitor (K CI ), and the catalyst and substrate (K S ) were computed from the kinetic data. A general mechanistic scheme is proposed for this reaction.

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Electrochemistry of Mercury

Orlik

Galus

2006

Encyclopedia of Electrochemistry

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The sections in this article are Double‐layer Properties of Hg /Water Interface Potential of Zero Charge Surface Charge Density and Capacitive Current Experimental and Theoretical Studies of the Hg /Water Interface Double‐layer Properties of Hg /Nonaqueous Media Interface Adsorption and Electrode Reactions at Hg Surface Deposition and Underpotential Deposition of Hg on Various Electrodes Underpotential Deposition of Mercury on Gold Electrodes Film Electrodes and Related Hg Electrodes Adsorption and Electrode Reactions of Inorganic Ions and Coordination Compounds of Metal Ions Analytical Applications Adsorption and Electrode Reactions Involving Organic Compounds Organic Compounds Containing Sulfur, Selenium, and Tellurium Organic Nitrogen Compounds Indicators and Dyes Vitamins and Antibiotics Enzymes and Coenzymes Other Organic Compounds Analytical Aspects of Adsorption of Organic Compounds Ammonium and Quaternary‐substituted Ammonium Amalgams

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Cathodic stripping voltammetry of thiosulphate at toxic concentrations

Cited by 6 publications

References 16 publications

Extraction, preconcentration and spectrophotometric determination of trace levels of thiosulfate in environmental waters

Extraction, preconcentration and spectrophotometric determination of trace levels of thiosulfate in environmental waters

Kinetic determination of trace amounts of thiosulfate based on its inhibitory effect

Electrochemistry of Mercury

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