Electrochemical Study of s‐Triazine Herbicides Transfer Across the Water/1,2‐Dichloroethane Interface

Abstract

The transfer of three s-triazine herbicides, atrazine (ATR), propazine (PRO) and prometrine (PROM), across the water/1,2-dichloroethane interface was investigated using cyclic voltammetry. A facilitated proton transfer mechanism from the aqueous to organic phase is demonstrated by the analysis of positive peak potential and peak current as a function of pH. It is shown that the determination of 2.5 Â 10 À5 M ± 5 Â 10 À4 M concentration of herbicides in aqueous phase may be possible under the experimental conditions employed.

Prometrine–Humic Acids Interactions Studied at a Water/1,2‐Dichloroethane Interface

“…to the first condition (absence of HA) and the transfer process responsible for the current peaks is the electrochemical H þ transfer facilitated by PROM as it was demonstrated in a previous paper [24]. Due to the high partition coefficient of PROM (log P ¼ 3.34), the partition equilibrium favors the access of these molecules to the organic phase where they act as proton carrier according to the following mechanism:…”

“…In a previous paper [24], the transfer of three s-triazine herbicides, atrazine, propazine and prometrine, across the water/1,2-dichloroethane interface was investigated using cyclic voltammetry. A facilitated proton transfer mechanism from the aqueous to organic phase was demonstrated by the analysis of positive peak potential and peak current as a function of pH.…”

An Electrochemical Approach to Quantitative Analysis of Herbicides and to the Study of Their Interactions with Soils Components

“…Several methods were employed in these investigations: macroscopic and molecular scale techniques, potentiometric titration data combined with EXAFS, ATR-FTIR and NMR, as well as spectroscopic data (Jonsson, 2007). The present chapter is focused in the progress made in the s-triazine quantification as well as in the study of their interactions with inorganic compounds of soils employing electrochemical methods applied at the interface between two immiscible electrolyte solutions (ITIES) (Juarez & Yudi, 2003;Juarez & Yudi 2008;Juarez & Yudi 2009). The interface between two immiscible electrolyte solutions and the transport of different ions across it are an important branch of electrochemistry because of their importance in the examination of heterogeneous kinetics and potential analytical applications (Reymond et al, 2000).…”

Quantitative Analysis of Prometrine Herbicide by Liquid–Liquid Extraction Procedures Coupled to Electrochemical Measurements

“…In a previous paper [31], the transfer of three s-triazine herbicides, atrazine, propazine and prometrine, across the water/1,2-dichloroethane interface was investigated using cyclic voltammetry. A facilitated proton transfer mechanism from the aqueous to organic phase was demonstrated by the analysis of positive peak potential and peak current as a function of pH.…”

“…The preconcentration of the analyte in the organic phase is possible due to its high solubility and partition coefficient (log P ¼ 3.34 [31]) in this solvent.…”