Voltammetric Determination of the Herbicide Linuron Using a Tricresyl Phosphate-Based Carbon Paste Electrode

Abstract

This paper summarises the results of voltammetric studies on the herbicide 3-(3,4-dichlorophenyl)-1-methoxy-1-methylurea (Linuron), using a carbon paste electrode containing tricresyl phosphate (TCP-CPE) as liquid binder. The principal experimental conditions, such as the pH effect, investigated in Britton-Robinson buffer solutions (pH 2.0–7.0), the peak characteristics for the analyte of interest, or instrumental parameters for the differential pulse voltammetric mode were optimized for the method. As found out, the best electroanalytical performance of the TCP-CPE was achieved at pH 2.0, whereby the oxidation peak of Linuron appeared at ca. +1.3 V vs. SCE. The analytical procedure developed offers good linearity in the concentration range of 1.25–44.20 μg mL−1 (1.77 × 10−4–5.05 × 10−6 mol L−1), showing—for the first time—the applicability of the TCP-CPE for anodic oxidations in direct voltammetry (without accumulation). The method was then verified by determining Linuron in a spiked river water sample and a commercial formulation and the results obtained agreed well with those obtained by the reference HPLC/UV determination.

Preparation of boron-doped hydrothermal carbon from glucose for carbon paste electrode

“…shows DPV behavior for the oxidation of 25 µg cm -3 linuron in 0.1 mol dm -3 H 2 SO 4 at CPE B/0.1 , CPE B/0.2 , CPE B/0.6 and CPE B/1 is fairly similar, with the exception of CPE H for which linuron oxidation peak is low intensity and shifted toward higher potential (1.34 V). Linuron oxidation peak potential (E p ) for boron doped CPEs is at 1.30 ± 0.01 V and this is close to E p of linuron obtained at boron doped glassy carbon electrode[18] and tricresyl phosphate-based CPE[28].The highest intensity (12.1 µA) and best analytical peak shape of linuron signal was obtained atCPE B/0.2 . The intensity of linuron peaks obtained at CPE B/0.1 , CPEB /0.6 and CPE B/1 are quite similar and they are in the range of 3.98 to 4.78 µA.…”

“…Also, the improvement of structural parameters could have a notable impact. Namely, the improvement of the structural parameters of turbostratic carbons increases the share of graphitic structure, which leads to an increase of the electrical conductivity of these materials and consequently their better electron transfer properties for Applied linuron determination method is based on our previous publication of linuron determination using boron doped glassy carbon [18] and graphite based CPE [28]. Fig.…”

“…Carbon paste electrode is widely used electrode in the fields of electrochemistry, due to its attractive advantages, such as simple preparation, low-cost implementation, wide potential window and low background current [26]. The most commonly used materials for CPE preparation are commercial graphite powders which are mixed with suitable binder ("pasting liquid") to form a homogeneous paste [27][28][29]. Carbon pastes are also made from less common carbon powders.…”

Square-Wave Voltammetric Determination of Nanomolar Levels of Linuron in Environmental Water Samples Using a Glassy Carbon Electrode Modified with Platinum Nanoparticles within a Dihexadecyl Phosphate Film

“…[2] Linuron [3-(3,4-dichlorophenyl)-1-methoxy-1-methylurea] is one of the most important commercial phenylureas that is widely used for the selective control of broadleaf weeds and grasses in fruit or field crops, cereals, and shelter belts. [3] A wide range of analytical methods have been applied to the analysis of linuron that are mostly based on chromatographic techniques. [4][5][6][7] Nevertheless, several methods are prone to drawbacks such as high cost, complicated and lengthy procedures, and unsuitability for practical use.…”

“…Gonzalez de la Huebra et al [9] determined linuron in soil extracts using a carbon fibre microelectrode. More recently, ÐorXević et al developed procedures used to detect linuron in spiked river water samples and a commercial formulation using a tricresyl phosphate-based carbon paste electrode, [3] a home-made non-modified glassy carbon electrode, and a modified boron-doped glassy carbon electrode. [10] de Lima et al employed a carbon paste electrode for electrochemical determination of linuron concentrations in water and vegetable extracts.…”