Coating of porous graphitic carbon nitride modified with titanium dioxide (OH-g-C3N4/TiO2) on Ag wire as an SPME fiber for extraction of lead

A new solid phase microextraction fiber was successfully synthesized using sol–gel technique. The selective and efficient graphitic carbon nitride modified with titanium dioxide (g-C3N4–TiO2) adsorbent was first recruited as fiber coating. The fabricated fiber was exploited for extraction and preconcentration of Pb(II) ions in real samples, using direct solid-phase microextraction method. The structure of the synthesized fiber was confirmed by FE-SEM, FT-IR, and EDX analyses. The optimum values of some parameters were obtained. The limit of detection (LOD) of the procedure was 0.16 μg L−1, and the relative standard deviations for repeatability (for one fiber) and reproducibility (fiber-to-fiber) of fabricated fibers (RSDs) were found to be 3.8% (n = 5) and 3% (n = 5), respectively. In addition, according to the results, the fiber approved that can be reused 17 times without a significant reduction in the percentage of analyte recovery. Finally, the method was used to extract and preconcentrate lead ions from real samples, viz. tea, medicinal plants, etc.