Abstract

Organophosphorous (OP) pesticides can cause many human diseases. In this study, the separation and determination of two organophosphorous pesticides (diazinon and methyl-parathion) in biological samples using solid-phase extraction method prior to their measurements by high�performance liquid chromatography (HPLC) were investigated. Herein, a new functionalized cerium-based metal�organic framework (MOF) bearing oxime moiety, denoted here UiO-66(Ce)-MO, was synthesized through two-synthetic steps from the pristine UiO-66(Ce) and then applied as an efficient porous adsorbent for the extraction of pesticides from biological samples. Various techniques including Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) analysis, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and Brunauer�Emmett�Teller (BET) analysis were used for the description of adsorbent. The optimization of variables was performed by Box�Behnken design combined with response surface methodology. The factors� effects including pH, eluent volume (EV), sample flow rate (SF) and eluent flow rate (EF) were also examined. The optimum conditions for both compounds were pH 5.5, eluent volume 0.6 mL, SF 2 mL min�1, and EF 0.2 mL min�1, leading to 97.1 and 96.0 removal of diazinon and methyl-parathion, respectively. Under the optimum conditions, the maximum adsorption capacity was obtained 454.5 mg g�1 for methyl-parathion and 476.2 mg g�1 for diazinon. The limit of detection (LOD) was found to be 0.04 μgL�1 for diazinon and 0.06 μgL�1 for methyl-parathion. Sensitivity analysis showed that pH plays a significant role on the efficiency of both organic pollutants. Remarkably, the results showed that this adsorbent outperforms the other UiO-66(Ce) samples and is suitable for separation and determination of these organic materials from water and biological real samples (blood plasma and urine). Graphical abstract: Figure not available: see fulltext. A porous oxime-functionalized Ce-MOF, UiO-66(Ce)-MO, was synthesized and applied for efficient extraction and determination of trace amounts of methyl-parathion and diazinon from water and biological samples. © 2022, The Author(s), under exclusive licence to Islamic Azad University.