Electric field-assisted synthesis of molecularly imprinted microelectrode for specific extraction of triazoles before quantification with HPLC

Abstract

Selective isolation and extraction is significant in the accurate monitoring of triazoles residuals in complex samples. In this connection, electric field reinforced solid-phase microextraction (ER-SPME) based on molecularly imprinted microelectrode (MIM) was developed for the specific capture of triazoles in environmental water and fruit juice samples prior to HPLC quantification. Using triadimenol (TRN) and acrylic acid as template and functional monomer, respectively, in-situ polymerization technique under the assistance of electric field was employed to conveniently prepare MIM. Results uncovered that the application of electric field during the polymerization procedure favored the improvement of specific recognition performance of MIM. In addition, the exertion of electric field at adsorption and desorption steps reinforced the extraction performance and shortened extraction duration. Chemical interactions played the key role in the adsorption and the extraction process belonged to single-layer adsorption. Selective adsorption behaviors and specific capture mechanism under electric field of MIM@ER-SPME towards TRN and its structural analogues were investigated in detail. After optimization of MIM@ER-SPME parameters, sensitive and reliable method for the monitoring of triazoles residuals in water and fruit juice samples was established. The achieved limits of detection (LODs) for water and juice samples were 0.011–0.022 μg/L and 0.014–0.097 μg/L, respectively. In comparison with documentary techniques, the established method exhibited satisfactory anti-interference performance, low LODs, high cost-effectiveness, superior reproducibility and low consumption of organic solvent in selective capture and determination of trace triazoles in actual samples.