Magnetized silica-doped graphene aerogel as an efficient adsorbent for magnetic dispersive solid-phase extraction of phenolic compounds and aniline from aqueous media
摘要
In this study, a novel magnetic silica-doped graphene aerogel (MSGA) was synthesized as an effective adsorbent for magnetic dispersive solid-phase extraction (M-dSPE) of phenolic compounds and aniline from aqueous media prior to GC-FID analysis. The MSGA combines the surface adsorption capability of graphene with analyte entrapment within a mesoporous silica structure and was characterized using EDX, SEM, XRD, and FTIR. The method was optimized for the extraction of phenol, 4-chlorophenol, o-cresol, and aniline. The results indicated that chloroform was the most effective desorption solvent. The optimal desorption volumes were 56 µL for phenol, 233 µL for 4-chlorophenol, 130 µL for o-cresol, and 140 µL for aniline. The optimal sample volume and adsorbent mass were determined to be 2.6–3.4 mL and 31–36 mg, respectively. Limits of detection ranged from 0.65 to 1.04 ng mL-1, while limits of quantification ranged from 1.98 to 3.15 ng mL-1. The relative standard deviations (RSD) were between 2.0% and 7.7%, and extraction efficiencies exceeded 86.1% in urine matrix. The MSGA adsorbent demonstrated good reusability, maintaining > 86.1% recovery after five consecutive cycles. The porous structure and magnetic properties of MSGA enhance the accuracy, speed, and operational simplicity of the extraction process. Although the adsorbent synthesis involves strong acids and organic solvents, the method significantly reduces solvent consumption during the extraction phase (only 200 µL chloroform per sample) compared to conventional liquid-liquid extraction. The MSGA-based M-dSPE method offers a practical balance of sensitivity, efficiency, and simplicity for monitoring phenolic compounds and aniline in complex matrices such as urine and wastewater.