Rapid hydrolysis and electrochemical detection of trace carbofuran at a disposable heated screen-printed carbon electrode

Abstract

A disposable heated screen-printed carbon electrode (HSPCE) is successfully fabricated. It demonstrates rapid responses to electrical heating and is easily elevated above the water boiling point by a high frequency alternating current. The temperature rise at the HSPCE was found to be strongly dependent on the square of the heating current and the electrode width. Carbofuran (CAF) could be rapidly hydrolyzed to carbofuran phenol at the HSPCE with raised temperature, and then determined at the same electrode at room temperature by differential potential voltammetry (DPV). The factors influencing the detection were examined, including pH, hydrolytic temperature and heating time. Under the optimum conditions, the detection linear range of CAF was from 4.0 × 10⁻⁷ to 4.0 × 10⁻⁴ mol L⁻¹ and the detection limit was 5.0 × 10⁻⁸ mol L⁻¹ (S/N = 3). This method was successfully applied to the analysis of CAF residues in real samples (spiked water, soil and vegetables), and satisfactory recoveries were obtained.