A facile adsorbent using graphitic carbon nitride with silver and nickel (Ag/ Ni@g-C₃N₄ nanocomposites) for Pb(II) extraction

Graphitic carbon nitride (g-C3N4) embedded with silver (Ag) and nickel (Ni), forms Ag/Ni@g-C3N4 nanocomposites, and has been explored as a novel adsorbent in the dispersive solid phase microextraction (DSPME) for Pb(II) determination, utilizing flame atomic absorption spectroscopy (FAAS) technique. The synthesized nanocomposites were analyzed using different characterization techniques including; X-ray diffraction (XRD), scanning electron microscope coupled with energy dispersive x-ray (SEM-EDX), and Fourier-transform infrared spectroscopy (FTIR). To optimize the extraction process, several analytical parameters were adjusted such as: pH, used adsorbent quantity, adsorption/elution time, sample volume, eluent volume, and amount of elution solvent as 8, 5 mg, 60 sec /30 sec, 30 mL/ 2.5 mL, and 0.5 mol/L HNO3, respectively, based on the recoveries of Pb(II). Matrix effects were also examined to ensure the accuracy of the method. The method's limit of detection (LOD) was 0.270 mu g/L, the limit of quantification (LOQ) was 0.91 mu g/L, and the preconcentration factor (PF) was 12. The percent relative standard deviation (%RSD) was below 10 %, and the coefficient of determination (R2) was 0.9952, indicating good precision and linearity. The accuracy of the method was confirmed by analyzing certified reference materials (CRMs). The concentration of Pb(II) in various dietary samples, and tap and industrial wastewater samples were determined by using the presented microextraction procedure.