Polarographic behaviour of some s-triazine herbicides and their determination by adsorptive stripping voltammetry at the hanging mercury drop electrode

Skopalová, Jana; Kotouček, Milan

doi:10.1007/bf00323342

Cited by 39 publications

(28 citation statements)

References 8 publications

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“…The plot of log(i) versus log(scan rate) for the anodic peak is a straight line that follows the relation log(i(A))=0.548·log(scan rate) (mV s -1 )-7.51; r=0.997; n=5; its slope is very close to that theoretically expected for a dominant diffusioncontrolled process, but the value of the origin suggests that the electrode reaction is partly accompanied by adsorption (in most systems adsorption processes are very fast, so under most experimental conditions the rate of adsorption is controlled by diffusion) [26][27]. At higher scan rates, the current growth of the cyclic voltammetric peaks decreases as a consequence of a ratedetermining step such as protonation [4][5]. The anodic and cathodic peak potentials shift toward more positive values and toward less positive potentials with the increasing scan rate, respectively.…”

Section: Optimization Of the Voltammetric Proceduressupporting

confidence: 58%

“…The choice of a suitable supporting electrolyte is very important for the determination of triazine herbicides [5,12].…”

Section: Optimization Of the Voltammetric Proceduresmentioning

confidence: 99%

“…Surveys of the distributions of triazine herbicides, such as ametryn (2-methylthio-4-ethylamino-6-isopropylamino-1,3,5-triazine) and atra-zine (2-chloro-4-ethylamino-6-isopropylamino-1,3, 5-triazine), in the environment are generally performed using gas chromatography, high performance liquid chromatography (HPLC) and thin-layer chromatogra-phy [3]. Among the electrochemical methods, polarog-raphy is the most commonly-used technique [4][5][6][7][8][9][10][11][12]. In addition to chromatographic methods, adsorptive stripping voltammetry (AdsV), the most sensitive electroanalytical technique currently available [13], has been proven to be suitable for trace analysis of pesticides [14].…”

Section: Introductionmentioning

confidence: 99%

“…Only mercury electrodes have been tested as working electrodes in AdsV, where they were used in the cathodic AdsV determination of s-triazine [4][5][6][10][11][12]. No study concerning anodic AdsV detection can be found in the literature.…”

Section: Introductionmentioning

confidence: 99%

“…No study concerning anodic AdsV detection can be found in the literature. In the procedures reported, the substances to be analysed were removed from water by solid phase extraction [5,8,10,12], and from wastewaters [6] and from soils by liquid extraction [12].…”

Section: Introductionmentioning

confidence: 99%

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Determination of ametryn in soils via microwave-assisted solvent extraction coupled to anodic stripping voltammetry with a gold ultramicroelectrode

et al. 2005

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An extraction-anodic adsorptive stripping vol-tammetric procedure using microwave-assisted solvent extraction and a gold ultramicroelectrode was developed for determining the pesticide ametryn in soil samples. The method is based on the use of acetonitrile as extraction solvent and on controlled adsorptive accumulation of the herbicide at the potential of 0.50 V (vs. Ag/AgCl) in the presence of Britton-Robinson buffer (pH 3.3). Soil sample extracts were analysed directly after drying and redis-solution with the supporting electrolyte but without other pre-treatment. The limit of detection obtained for a 10 s collection time was 0.021 lg g -1. Recovery experi-ments for the global procedure, at the 0.500 lg g -1 level, gave satisfactory mean and standard deviation results which were comparable to those obtained by HPLC with UV detection.

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Section: Optimization Of the Voltammetric Proceduressupporting

confidence: 58%

“…The choice of a suitable supporting electrolyte is very important for the determination of triazine herbicides [5,12].…”

Section: Optimization Of the Voltammetric Proceduresmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Determination of ametryn in soils via microwave-assisted solvent extraction coupled to anodic stripping voltammetry with a gold ultramicroelectrode

et al. 2005

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Monitoring of the photochemical degradation of metamitron and imidacloprid by micellar electrokinetic chromatography and differential‐pulse polarography

et al. 1999

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The photochemical degradation of metamitron (4-amino-4,5-dihydro-3-methyl-6-phenyl-1,2,4-triazin-5-one) and imidacloprid (1-(6-chloro-3-pyridylmethyl)-N-nitroimidazolidin-2-ylideneamine) has been investigated by differential-pulse polarography (DPP) and micellar electrokinetic chromatography (MEKC); the degradation pathways of these pesticides were elucidated and their degradation products proposed.The electrochemical study of imidacloprid by DPP at different pH values demonstrated the occurrence of two different reduction processes; at pH 6.8, two peaks at À0.90 V and À1.38 V, respectively, were obtained, which are related to the photochemical reduction processes. The photochemical degradation of imidacloprid caused by sunlight was polarographically monitored and its degradation products elucidated. The polarographic reduction of deaminometamitron (obtained by photochemical reduction of metamitron) yielded two peaks at À0.62 and À1.37 V, which are related to the reduction of the C=N bonds. The effect of sunlight on the reduction of metamitron was monitored by DPP, and an increase of the concentration of the degradation products was observed with time.MEKC with UV-visible detection was used to separate the pesticides and the products of their photochemical degradation, which were identi®ed in combination with DPP.

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Electrochemical Reduction of Prometryne and the Other 2-Methylthio-4,6-dialkylamino-s-triazine Herbicides at Mercury Electrodes

Skopalová¹,

Lemr

Kotouček

et al. 1998

Electroanalysis

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The electrochemical behavior of the herbicide prometryne was studied in aqueous solutions by DC polarography, differential pulse and cyclic voltammetry and by constant potential coulometry. Only the protonated form of prometryne can be reduced at pH < 6.5. The electrode process includes two irreversible steps. The two-electron reduction of the C-S bond leads to its splitting and a release of methylthiol molecule. The triazine ring of the reduction product is immediately reduced under the uptake of two electrons. Both the intermediate and final products of constant potential electrolysis were identified using chromatographic techniques and mass spectrometric analysis. The reduction mechanism of other 2-methylthio-4,6-dialkylamino-s-triazines is identical.

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Polarographic behaviour of some s-triazine herbicides and their determination by adsorptive stripping voltammetry at the hanging mercury drop electrode

Cited by 39 publications

References 8 publications

Determination of ametryn in soils via microwave-assisted solvent extraction coupled to anodic stripping voltammetry with a gold ultramicroelectrode

Determination of ametryn in soils via microwave-assisted solvent extraction coupled to anodic stripping voltammetry with a gold ultramicroelectrode

Monitoring of the photochemical degradation of metamitron and imidacloprid by micellar electrokinetic chromatography and differential‐pulse polarography

Electrochemical Reduction of Prometryne and the Other 2-Methylthio-4,6-dialkylamino-s-triazine Herbicides at Mercury Electrodes

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