Synthesis and characterization of pyridine-functionalized magnetic mesoporous silica and its application for preconcentration and trace detection of lead and copper ions in fuel products

Abstract

We present a study on the synthesis, characterization and application of a pyridine-functionalized magnetic mesoporous silica material (called Py-Fe₃O₄@MCM-41) as an adsorbent for the solid phase extraction of trace quantities of lead and copper ions. The modified Fe₃O₄@MCM-41 can be easily separated from an aqueous solution by applying an external magnetic field. Effects of pH, amount of functionalized Fe₃O₄@MCM-41, extraction time, type and quantity of eluent, desorption time, and interfering ions on the extraction efficiency were evaluated and optimized. Lead and copper ions were then quantified using a flame atomic absorption spectrophotometer. Under the optimized conditions, the detection limit for lead and copper ions was 0.1 μg L⁻¹ and 0.08 μg L⁻¹, respectively and the maximum adsorption capacity of the synthesized sorbent for lead and copper ions was 287 mg g⁻¹ and 194 mg g⁻¹, respectively. The Py-Fe₃O₄@MCM-41 sorbent was characterized by thermogravimetric analysis, differential thermal analysis, transmission electron microscopy, Fourier transform infrared spectrometry and X-ray diffraction.