Quantification of Higher Molecular Weight Polycyclic Aromatic Hydrocarbons in Water Samples by Modified Magnetic Nanoparticle and Gas Chromatography–Mass Spectrometry

A novel and unconventional of pre-concentration method and extraction of selected HMW-PAHs (higher molecular weight polycyclic aromatic hydrocarbons) from water samples have been developed. The novel approach benefits from the high attraction between HMW-PAHs and the modified magnetic nanoparticles. In this work, milligrams of magnetic nanoparticles are initially added to the aqueous solution and dispersed in all parts of the solution by shaking. To collect the nanoparticles, a neodymium magnet is placed on the outer surface of the container, followed by discarding the solution. The analyte in the collected solid phase is then released into 1-butanol followed by gas chromatography–mass spectrometry Optimization of the experiment parameters has guided to a Gas chromatography–mass spectrometric method of detection with acceptable analytical figures of merit. The LOD (limits of detection) ranged from 0.010 (Benzo(b) fluoranthene) to 0.08 (Benzo(k) fluoranthene) µg/L. The relative standard deviations (RSD) at medium calibration concentrations differ from 3.12 (Benzo(b)fluoranthene) to 6.31% (Benzo(a)pyrene). The R% (analytical recoveries) from tap water samples of the three regulated HMW-PAHs from six locations in Baghdad city range from 63.88 (Benzo(k)fluoranthene) to 91.01 (Benzo(a)pyrene). The entire method of extraction uses lower than 150 μL of organic-based solvents(butanol) for each sample, which marks it a friendly method to the environment. The small extracting solution volume makes the modified nanoparticle a relatively in-expensive extraction procedure.