Rapid solid-phase microextraction of polycyclic aromatic hydrocarbons in water samples by a coated through-pore...

A novel solid-phase microextraction device based on a through-pore sintered titanium disk (ST-SPME) was prepared and evaluated for the rapid extraction of organic pollutants from aqueous samples. The through-pores embedded in a sintered titanium disk were enlarged by HCl etching, yielding more Ti-O functional groups and a rough surface that should benefit the covalent binding of extraction phase with the disk. The large inner surface area (850mm(2)) of the disk and narrow through-pores (100µm) significantly increase the extraction capacity and mass transfer rate. In addition, the resistance to water flow of the ST-SPME disk is rather low, yielding a back pressure of only 100kPa at a flow rate of 50mL/min. The extracted target compounds are thermally desorbed by a thermal desorption unit and transferred to a GC or GC-MS system. Taking polydimethylsiloxane as the extraction phase and 16 types of polycyclic aromatic hydrocarbons (PAHs) as model analytes, the extraction and desorption conditions were systematically investigated. The optimized extraction time was only 2min for 100mL of water sample. Absolute recoveries were between 5.93% and 23.02%, which are similar to that of stir bar sorptive extraction. The LODs and RSDs were 0.06-3.20ng/L (S/N=3) and 0.57-7.08%, respectively. The method showed good linearity in the range of 0.01-10µg/L with a squared determination coefficient R(2)≥0.9939. As our method was suitable for the measurement of organic pollutants in the water phase, the ST-SPME/GC-MS method was assessed by analyzing three filtered real environmental samples. Some PAHs were detected at the ng/L level in river water and sea water.