Development of an environmentally friendly method for the determination of prednisolone in natural waters using unmodified boron-doped diamond electrode

Water pollution by endocrine disruptors (EDs) is becoming a global environmental problem. The main ecotoxicological concern with these substances involves their evident capacity to affect the reproduction of the species and interfere with their healthy development. This work developed an electroanalytical method for determining prednisolone (PDN) in natural waters using the boron-doped diamond working electrode (BDDE). Studies by cyclic voltammetry showed that PDN presents three oxidation peaks, at 0.7, 0.9, and 1.1 V vs. Ag/AgCl (KCl 3.0 mol L⁻¹), which depend on the reduction peak at − 1.1 V, with characteristics of irreversible processes, controlled by diffusion of the species. Using the square wave voltammetry technique, the analytical curve obtained for ultrapure water showed linearity from 5.00 to 123.46 μmol L⁻¹. In ultrapure water, the limit of detection (LD) and limit of quantification (LQ) values were 1.22 μmol L⁻¹ and 4.02 μmol L⁻¹, respectively. In natural waters, it presented an LD of 1.19 μmol L⁻¹ and LQ of 3.94 μmol L⁻¹, with 88.6% and 108.2% recovery tests. The results indicated that this low-cost method, with fewer sample preparation steps and without organic solvents, can be used to determine PDN in natural waters.