Magnetic amine functionalized zinc based metal organic framework as a sorbent for magnetic solid-phase extraction of selected pesticides followed by high-performance liquid chromatography-ultraviolet detection

Herein, a low-cost extraction technique was developed for the preconcentration and determination of selected pesticides. Herein, a new magnetic metal-organic framework (Fe₃O₄@TMU-16-NH₂) was produced using a high-performance, low-cost, quick and environmentally friendly approach through the coordination of 2,5-bis(4-pyridyl)-3,4-diaza-2,4-hexadiene (4-bpdh) ligand to the Zn(NO 3 ) 2 ·6H 2 O salt under hydrothermal strategy. The proposed Fe 3 O 4 @TMU-16-NH 2 (TMU= Tarbiat Modares University) sorbent shows promising prospects as a new sorbent owing to its unique structural features, including abundant functional groups, and suitable stability. This sorbent was employed for magnetic solid-phase extraction (MSPE) of target pesticides (cyromazine, diazinon, fipronil, tebuconazole and chlorpyrifos) in complex matrices. The key experimental parameters affecting the extraction efficiency, including the type of eluent, sorbent amount, salt concentration, pH of the sample solution, eluent volume, desorption time, and extraction time, were systematically studied and optimized. Under optimized condition, the developed method provided a linear dynamic ranges (LDRs) of 0.50–200.00 µg L⁻¹, limits of detection (LODs) in the range of 0.12–0.23 µg L⁻¹, limits of quantification (LOQs) between 0.43 and 0.78 µg L⁻¹, enrichment factors (EFs) of 172.00–186.00, and absolute recoveries of 51.6-55.8%. The greenness of the proposed method was evaluated using the BAGI and AGREEprep metrics. The obtained BAGI and AGREEprep scores were 70 and 0.70, respectively, indicating favorable green analytical performance. The validated method was employed for the analysis of real samples, including cucumber, tomato, apple, and apricot, with acceptable values of relative and spiking recoveries (higher than 90%) approving its reliability and applicability for analysis of complex matrices.