Response surface methodology optimization for enhancing the analytical performance of a hanging mercury drop electrode for imidacloprid

Abstract

We introduce an innovative approach to enhance the quantification of the pesticide imidacloprid (IMD) using square wave voltammetry (SWV) with a mercury drop electrode (HMDE). Through systematic factorial designs, we meticulously adjusted both the chemical and instrumental parameters of SWV, with a particular focus on optimizing the peak reduction current. Using response surface methodology (RSM) provided comprehensive insights into the system behavior. The optimal conditions were found at a pH of IMD solution of 7.45, Accumulation Potential (Eacc) of 0.70 V, Accumulation Time (tacc) of 46.45 s, Frequency (F) of 200 Hz, Amplitude (Esw) of 0.090 V, and Step (dE) of 0.0080 V. With these optimized parameters, we constructed a calibration curvespanning a concentration range from 0.5 to 5.0 × 10-7 mol/L. The method exhibited a remarkably low limit of detection (LOD) at 3.65 × 10-8 mol/L and a limit of quantification (LOQ) of 5.01 × 10-8 mol/L. Subsequently, we rigorously assessed the methodology’s effectiveness by quantifying IMD in various water samples from the C´ordoba area, achieving consistently near 100 % recovery values.