Agarose film liquid phase microextraction combined with gas chromatography–mass spectrometry for the determination of polycyclic aromatic hydrocarbons in water

Agarose film liquid phase microextraction (AF-LPME) procedure for the extraction and preconcentration of polycyclic aromatic hydrocarbons (PAHs) in water has been investigated. Agarose film was used for the first time as an interface between donor and acceptor phases in liquid phase microextraction which allowed for selective extraction of the analytes prior to gas chromatography–mass spectrometry. Using 1-octanol as acceptor phase, high enrichment factors in the range of 57–106 for the targeted analytes (fluorene, phenanthrene, fluoranthene and pyrene) were achieved. Under the optimum extraction conditions, the method showed good linearity in the range of 0.1–200 μg L−1, good correlation coefficients in the range of 0.9963–0.9999, acceptable reproducibility (RSD 6.1–9.2%, n = 3), low limits of detection (0.01–0.04 μg L−1) and satisfactory relative recoveries (92.9–104.7%). As the AF-LPME device was non-expensive, reuse or recycle of the film was not required, thus eliminating the possibility of analytes carry-over between runs. The AF-LPME technique is environment-friendly and compatible with the green chemistry concept as agarose is biodegradable polysaccharide extracted from seaweed and the procedure requires small volume of organic solvent and generates little waste. The validated method was successfully applied to the analysis of the four analytes in river water samples.