In situ electrodeposition of Cu-BDC metal–organic framework on pencil graphite substrate for solid-phase microextraction of some pesticides.

The study focuses on the electrochemical deposition of copper benzene-1,4-dicarboxylate framework (Cu-BDC MOF) on the surface of a very cheap pencil graphite (PG) substrate for utilization as the sorbent in fiber solid-phase microextraction (SPME) of two chosen pesticides, including abamectin and amitraz for the first time. The extracted pesticides were quantified by high-performance liquid chromatography–ultraviolet detection (HPLC–UV). The UV detector was set at 236 nm wavelength. Based on the optimized condition, the presented technique showed a good linear range (2–500 µg L⁻¹ and 2–100 µg L⁻¹), suitable limits of detections (LODs = 0.60 and 0.5 µg L⁻¹), satisfactory enhancement factors (EFs = 128 and 105), good absolute recoveries (ARs% = 64% and 53%) and spiking recoveries in the range 87.4–110.0% for amitraz and abamectin, respectively. Intra- and inter-day relative standard deviations were found within the range 1.2–3.8% and 0.6–1.9%, respectively. The method was successfully employed for the quantification of the selected pesticides in strawberry juice, lemon juice, orange juice, tomato juice, and honey. [ABSTRACT FROM AUTHOR]