Magnetized graphene layers synthesized on the carbon nanofibers as novel adsorbent for the extraction of polycyclic aromatic hydrocarbons from environmental water samples

- m-G/CNF nanocomposites were designed and synthesized.
- The new material exhibited good chemical stability and was used as a MSPE material.
- The proposed method achieved low LODs, wide linearity, and good precision for PAHs.
- The material was used for the enrichment and determination of PAHs at trace levels.

The application of magnetized graphene (G) layers synthesized on the carbon nanofibers (CNFs) (m-G/CNF) was investigated as novel adsorbent for the magnetic solid-phase extraction (MSPE) of polycyclic aromatic hydrocarbons (PAHs) in water samples followed by gas chromatography-flame ionization detector (GC-FID). Six important parameters, affecting the extraction efficiency of PAHs, including: amount of adsorbent, adsorption and desorption times, type and volume of the eluent solvent and salt content of the sample were evaluated. The optimum extraction conditions were obtained as: 5 min for extraction time, 20 mg for sorbent amount, dichloromethane as desorption solvent, 1 mL for desorption solvent volume, 5 min for desorption time and 15% (w/v) for NaCl concentration. Good performance data were obtained at the optimized conditions. The calibration curves were linear over the concentration ranges from 0.012 to 100 ng mL−1 with correlation coefficients (r) between 0.9950 and 0.9967 for all the analytes. The limits of detection (LODs, S/N = 3) of the proposed method for the studied PAHs were 0.004-0.03 ng mL−1. The relative standard deviations (RSDs) for five replicates at two concentration levels (0.1 and 50 ng mL−1) of PAHs were ranged from 3.4 to 5.7%. Appropriate relative recovery values, in the range of 95.5-99.9%, were also obtained for the real water sample analysis.