Disposable clay-coated screen-printed electrode for amitrole analysis

A preanodized nontronite-coated screen-printed electrode (NSPE*) was developed for the sensitive detection of the pesticide amitrole by square-wave voltammetry (SWV) and flow injection analysis (FIA). The preanodization process was essential to improve the sensitivity because of the existence of higher iron oxidation state in the interlayer of nontronite clay. Factors influencing the SWV and FIA responses were evaluated in this study. Under optimized conditions, the calibration curve showed a linear range up to 300 and 500µM for SWV and FIA, respectively, in pH 4.5 PBS. The detection limit (S/N=3) was 0.33µM in SWV and 0.07ng in a 20µl sample loop by FIA. The high precision and sensitivity of the method offers an easy route for direct determination of amitrole.