Determination of polycyclic aromatic hydrocarbons in waters by ultrasound-assisted emulsification-microextraction and gas chromatography–mass spectrometry

An ultrasound-assisted emulsification-microextraction (USAEME) procedure was developed for the extraction of US EPA 16 polycyclic aromatic hydrocarbons (PAHs) in 10 mL of water samples, with subsequent determination by gas chromatography–mass spectrometry (GC–MS). After determination of the most suitable solvent and solvent volume, several other parameters (i.e., extraction time, centrifugation time and ionic strength of the sample) were optimized using a 23 factorial experimental design. Limits of detection ranged from 0.001 to 0.036 μg L−1. The developed procedure was applied to fortified distilled water with different fortification levels (0.5, 2 and 5 μg L−1). Recoveries were over 92% and relative standard deviations of the recoveries were below 8%. The efficiency of the USAEME was compared with traditional liquid–liquid extraction (LLE) and solid-phase extraction on real water samples (i.e., tap water, well water and surface (lake) water as well as domestic and industrial wastewaters). The USAEME showed comparable efficiencies especially with LLE. The developed USAEME was demonstrated to be robust, viable, simple, rapid and easy to use for the determination of PAHs in water samples by GC–MS.