Electrochemical oxidation of triticonazole on boron-doped diamond-based electrodes for analysis of real matrices

The voltammetric behavior of the triazole fungicide triticonazole (TTC) was investigated for the first time using a boron-doped diamond electrode (BDDE). TTC provides several current responses on BDDE. An irreversible first anodic peak was observed at a potential of +1.5 V ( vs. Ag/AgCl/KCl, sat.), while a second indistinctive oxidation peak was observed at approximately +2.0 V in the supporting electrolyte current onset, and a reduction peak was observed at a potential of 0 V. The mechanism of TTC oxidation was proposed and supported by theoretical calculations, electrochemical measurements, and the exhaustive electrolysis accompanied with product analysis using liquid chromatography with mass spectrometry (LC/MS). Subsequently, a voltammetric method for the determination of the fungicide was developed, employing square-wave voltammetry. This method exhibited a low limit of detection (0.125 µmol L −1 ), a broad linear dynamic range (0.5–20 µmol L −1 ), and excellent recovery in the analysis of pesticide preparations. Considering the low concentrations of TTC in natural waters, a sample pre-concentration technique using solid phase extraction was developed for these applications. The novel method was successfully transferred to screen-printed sensors with BDD electrodes (SP/BDDE). The obtained results indicate that SP/BDDE enable an expansion of the linear dynamic range (0.25–60 µmol L −1 ) of the proposed method. SP/BDDEs were successfully applied in the analysis of pesticide formulations and demonstrated 1.68–1.85 times better sensitivity. • First report on the electrochemical oxidation of the triazole fungicide triticonazole. • LC/MS analysis and DFT calculations performed to propose mechanism of oxidation. • New voltammetric method for triticonazole determination in preparations and natural water. • Potential pesticide interferents in real matrices identified. • Application of screen-printed sensors with BDDE suitable for miniaturized analyzers.