Electrosynthesized bimetallic-MOF modified graphite Fiber for electro-assisted solid phase microextraction of Ametryn...

In this study, a bimetallic nickel‑cobalt metal-organic framework (NiCo-MOF) was electrosynthesized in situ on a graphite pencil fiber (GPF) and used as a sorbent in electro-assisted solid phase microextraction (EA-SPME) of ametryn (AME). Extracted AME was desorbed and analyzed using gas chromatography-flame ionization detection (GC-FID). Two central composite designs (CCD) were used to multivariate optimization of both NiCo-MOF electrosynthesis and extraction conditions. The method achieved a limit of detection (LOD) of 1 ng mL^-1, a limit of quantitation (LOQ) of 3.5 ng mL^-1 and a linear dynamic range (LDR) of 3.5-500 ng mL^-1 (R² = 0.9986) for deionized water. The method showed good precision with relative standard deviation (RSD %) in the range of 2.7-5.0% and good relative recoveries (RR %) in the range of 106-113% for real samples. These results demonstrate the method's sensitivity, reliability, and potential for efficient preconcentration and determination of AME in complex food matrices.