Synthesis of a bimetal-organic framework-cobalt oxide nanoflowers (Ni/ Co-MOF@Co₃O₄ NFs) for sensitive tebuconazole extraction from fruit juice and water samples using micro-solid phase extraction-HPLC-DAD

Tebuconazole (TBZ) is a widely used triazole fungicide that poses potential risks to human health and the environment due to its persistence in food and water. Effective monitoring of TBZ residues is crucial for ensuring food safety and environmental protection. This study presents a novel method for synthesizing Ni/Co-MOF@Co3O4 nanoflowers (NFs) and their application in extracting TBZ from water and fruit juice samples via microsolid phase extraction (mu -SPE). Ni/Co-MOF@Co3O4 NFs was synthesized using the hydrothermal technique followed by calcination. The synthesized nanoflowers were characterized through SEM, XRD, and FT-IR analyses. Optimal extraction conditions were established at pH 8, using 10 mg of adsorbent, with adsorption and desorption times of 3 and 2 min, respectively. TBZ analysis was conducted using HPLC with a Poroshell 120 ECC18 column and a diode array detector (DAD). The method demonstrates excellent recovery rates (90-102 %) and RSD% of 3.7 % in spiked fruit juice and natural water samples. The analytical performance showed a wide linear range (1-2000 mu g L- 1) with a high correlation coefficient (R2 = 0.9998), a detection limit of 4.0 ng L- 1, and a quantification limit of 13.0 ng L- 1. This approach is fast, simple, and highly sensitive, offering a reliable technique for detecting trace levels of TBZ in food and water environments.