Facile fabrication of composited solid phase microextraction thin membranes for sensitive detections of trace hydroxylated polycyclic aromatic hydrocarbons in human urine.

Solid phase microextraction (SPME) has potential to be used for the high-performance enrichments of hydroxylated polycyclic aromatic hydrocarbons (OH-PAHs), which are important biomarkers of PAH exposure. By choosing suitable adsorbent, it is conducive to fabricate new-type of SPME device for improved extraction efficiencies towards OH-PAHs. In this study, a novel method of surface solvent evaporation has been proposed to fabricate SPME thin membrane, integrating the advantages of polydimethylsiloxane (PDMS) and different porous adsorbents. The powdery metal organic framework (Uio66-NH2), porous polymer (powdery polymer aerogel, PPA) and ordered mesoporous carbon (OMC) have been chosen as typical adsorbents and fabricated as thin membranes successfully, indicating the universality of the proposed method for membrane fabrication. Comparing the extraction efficiencies of three prepared membranes towards OH-PAHs, the OMC-PDMS membrane has demonstrated best enrichment efficiencies. The OMC-PDMS membrane was used for the enrichments of trace OH-PAHs in human urine of both smokers and nonsmokers, combining with liquid chromatographic tandem mass spectrometry (LC-MS/MS). The detection limits were in the range of 0.15-0.39 ng L-1, and satisfactory recoveries were found to be 82.1%-115%. It can be seen that the universal strategy to fabricate SPME membrane is helpful to achieve broad-spectrum or selective enrichments of target analytes from complex matrix by simple modulation of membrane components.