Ionic liquid coated magnetic nanoparticles for the gas chromatography/mass spectrometric determination of polycyclic aromatic hydrocarbons in waters

In this paper, ionic liquid coated magnetic nanoparticles (IL-MNPs) have been prepared by covalent immobilization. The as-synthesized MNPs have been successfully used as sorbent for the extraction of polycyclic aromatic hydrocarbons (PAHs) from water samples, the analytes being finally determined by gas chromatography/mass spectrometry. The influence of several experimental variables (including the ionic strength, amount of MNPs, sample volume, agitation time and desorption solvent) has been considered in depth in the optimization process. The developed method, which has been analytically characterized under its optimal operation conditions, allows the detection of the analytes in the samples with method detection limits in the range from 0.04 μg L−1 (fluoranthene) to 1.11 μg L−1 (indeno(1,2,3-cd)pyrene). The repeatability of the method, expressed as relative standard deviation (RSD, n = 7), varies between 4.0% (benzo[b]fluoranthene) and 8.9% (acenaphthene), while the enrichment factors are in the range from 49 (naphthalene) to 158 (fluoranthene). The proposed procedure has been applied for the determination of thirteen PAHs in water samples (tap, river, well and reservoir ones) with recoveries in the range from 75 to 102%.