A combined microextraction procedure for isolation of polycyclic aromatic hydrocarbons in ambient fine air particulate matter with determination by gas chromatography-tandem mass spectrometry.

A novel combined vortex-assisted dispersive liquid-liquid microextraction (VA-DLLME)-micro-solid-phase extraction (μ-SPE) procedure for polycyclic aromatic hydrocarbons (PAHs) in ambient fine particulate matter of aerodynamic diameter of  ≤ 2.5 µm (PM), was developed. PM was collected on polytetrafluoroethylene (PTFE)-coated glass fiber filter, that was first processed by ultrasonicating in aqueous solution. Then, VA-DLLME, followed by µ-SPE, were applied to the solution using 1-octanol and graphene oxide as extractant and sorbent, respectively for extracting the PAHs. The PAHs were determined by gas chromatography-tandem mass spectrometry (GC-MS/MS). Parameters affecting the extraction efficiency including selection of the sorbent, duration of DLLME and µ-SPE, desorption solvent type, and ultrasonication-assisted desorption time were investigated. Under the optimum extraction conditions, the method exhibited linear ranges of 0.5-50 μg/L and 0.5-100 μg/L depending on the analytes. The limits of detection were in the range of 0.013 μg/L-0.135 μg/L. The developed method was applied to determine the PAHs in genuine PM samples collected on PTFE glass fiber filters. The concentration levels in the atmospheric PM were determined to be from below the limit of quantification to 0.135 ng/m. The relative recoveries obtained from spiked concentrations at 1 μg/L and 5 μg/L were in the range 57-88% with relative standard deviations <14%.