TiO2 nanotubes as solid-phase extraction adsorbent for the determination of polycyclic aromatic hydrocarbons in environmental water samples

An analytical method based on TiO2 nanotubes solid-phase extraction (SPE) combined with gas chromatography (GC) was established for the analysis of seven poly cyclic aromatic hydrocarbons (PAHs): acenaphtylene, acenaphthene, anthracene, fluorene, phenanthrene, fluoranthene and pyrene. Factors affecting the extraction efficiency including the eluent type and its volume, adsorbent amount, sample volume, sample pH and sample flow rate were optimized. The characteristic data of analytical performance were determined to investigate the sensitivity and precision of the method. Under the optimized extraction conditions, the method showed good linearity in the range of 0.01-0.8 μg/mL, repeatability of the extraction (RSD were between 6.7% and 13.5%, n = 5) and satisfactory detection limits (0.017-0.059 ng/mL). The developed method was successfully applied to the analysis of surface water (tap, river and dam) samples. The recoveries of PAHs spiked in environmental water samples ranged from 90% to 100%. All the results indicated the potential application of titanate nanotubes as solid-phase extraction adsorbents to pre-treat water samples.