Phenyl propyl functionalized hybrid sol-gel reinforced aluminum strip as a thin film microextraction device for the trace quantitation of eight PCBs in liquid foodstuffs.

In the present study, a low-cost, convenient and reliable thin film coating was developed as the extraction phase. The new sorbent was obtained by chemical bond formation between the hybrid sol-gel precursors and aluminum strip substrate in the first step and subsequent functionalization by phenyl propyl groups. The surface properties of the synthesized sorbent were characterized by Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). Eight polychlorinated biphenyl (PCB) homologs were effectively extracted by using the self-made device in thin film microextraction (TFME) set-up followed by gas chromatography-mass spectrometry (GC-MS) determination. The influencing factors, including extraction and desorption solvent, desorption solvent volume, extraction and desorption time, extraction temperature, agitation speed, salt addition, and matrix effect were investigated. Under the optimized conditions, the limits of detection (at S/N ratio of 3) were found to be 1-3 ng L and the linearity was in the range of 10-1000 ng L. The method precision values calculated as relative standard deviations (RSDs%), were in the range of 6.8-11.0% (intra-day), and 9.0-12.4% (inter-day). This work was successfully applied to enrichment and trace levels determination of PCB congeners in orange juice, cola drink, milk, beer, and honey. The evaluations also showed satisfactory recoveries (70.6-103.5%) for different spiked real samples.