[BMIM]Cl‐AgNPs Immobilized on Eggshell Membrane as an Adsorbent for Solid Phase Extraction of Sulfamethoxazole in Lake and Tap Water

An alternative solid phase extraction (SPE) material, 1‐butyl‐3‐methylimidazolium chloride–silver nanoparticles/eggshell membrane ([BMIM]Cl‐AgNPs/ESM), is developed by synthesizing [BMIM]Cl‐AgNPs using a simple reduction method and immobilizing directly on ESM. The newly developed material is successfully applied for extraction and detection of sulfamethoxazole (SMX) in environmental aqueous samples via a high‐performance liquid chromatography‐diode array detector (HPLC‐DAD). Characterization is accomplished by Fourier transform infrared (FTIR) and field emission scanning electron microscopy/energy dispersive X‐ray (FESEM/EDX), confirming the presence of [BMIM]Cl‐AgNPs on ESM. The optimization of [BMIM]Cl‐AgNPs/ESM‐based SPE method is studied by the one variable at a time (OVAT) approach. Method validation shows good linearity (R2 = 0.9995) in the range of 10–500 µg L−1, with the detection and quantification limits determined to be 3.07 and 9.31 µg L−1 respectively. Additionally, a reusability study shows the developed material can extract SMX up for three cycles without significant reduction in its efficiency. Excellent recoveries (90.07–104.08%) in spiked tap and lake water demonstrate the potential of [BMIM]Cl‐AgNPs/ESM for trace‐level detection of pollutants.