Phenethylamine functionalized hybrid sol–gel reinforced aluminum foil as a thin film microextraction device for the trace analysis of eight PCBs in edible liquids prior to GC-MS quantitation

A novel sol-gel coating on an aluminum foil was produced and applied as a thin film microextraction (TFME) device. Eight selected polychlorinated biphenyls (PCBs) were employed as model compounds to evaluate the extraction performance of the synthesized sol-gel. The analysis was performed using gas chromatography-mass spectrometry [1]. First, pieces of aluminum foil (5 cm × 0.5 cm) was etched in concentrate NaOH and 10% HCl respectively. Then aluminum foil was coated with a thin hybrid sol-gel film of methyltrimethoxysilane–tetraethoxysilane (MTMOS–TEOS). Afterward, Phenethylamine bounded chloropropyltrimethoxysilane used for functionalization of sol-gel reinforced aluminum foil. Its morphology and surface properties were characterized using Fourier transform infrared spectroscopy, scanning electron microscopy and energy dispersive spectroscopy. The performance of new sorbent functionalized with phenethylamine was compared with bare aluminum foil and aluminum foil coated MTMOS–TEOS. Aromatic functional groups in final sorbent leading up to suitable π interactions with PCBs resulting higher extraction efficiency [2]. The parameters affecting the efficiency of TFME such as extraction solvent type and volume, extraction and desorption time, temperature, stirring rate and salt effect were investigated and optimized. Under the optimal conditions, the limit of detection (S/N = 3) was 1 ng L-1 and the linearity was in the range of 10 to 1000 ng L-1. The method precision expressed as relative standard deviations (RSD) was 7.0-11 % (intra-day), and of 9.0-12.4% (inter-day) respectively. Finally, our method was successfully applied for trace determination of PCBs in orange juice, cola drink, milk, beer, and honey with acceptable performance.