Fabrication of a novel magnetic metal–organic framework functionalized with 2-aminothiophenol for preconcentration of trace silver amounts in water and wastewater

Abstract

Herein, a novel magnetic metal–organic framework functionalized (MMOF) with 2-aminothiophenol (2-ATP) was fabricated and employed for separation/preconcentration of trace silver amounts. At first magnetite nanoparticles (Fe₃O₄ NPs) were synthesized and then coated with SiO₂. Thereafter, the Fe₃O₄@SiO₂ nanoparticles were modified with 2-ATP. Finally, the functionalized MMOF was prepared by the fabrication of MIL-101(Cr) in the presence of Fe₃O₄@SiO₂@2-ATP NPs. MIL-101(Cr)/Fe₃O₄@SiO₂@2-ATP nanocomposite was characterized with FT-IR, SEM, elemental analysis, XRD and VSM and then utilized in the separation/determination of silver ions in various real samples. The effects of diverse experimental variables such as pH, uptake time, adsorbent amount, desorption time, eluent concentration and volume were studied comprehensively employing experimental design methodology. After optimization, LOD and linearity were 0.05 ng mL⁻¹ and 0.2–200 ng mL⁻¹, respectively. Repeatability of the new method was determined based on RSD value for 5, 50, 150 ng mL⁻¹ (n = 5) concentrations which was 9.3%, 6.8% and 4.5%, respectively. Ultimately, the outlined method was utilized in the separation/determination of silver ions in various water and wastewater samples satisfactorily.