Polythiophene/hexagonally ordered silica nanocomposite coating as a solid-phase microextraction fiber for the determination of polycyclic aromatic hydrocarbons in water

Abstract

A highly porous fiber coated with polythiophene/hexagonally ordered silica nanocomposite was prepared for solid-phase microextraction (SPME). The prepared nanomaterial was immobilized onto a stainless-steel wire for the fabrication of the SPME fiber. Polythiophene/hexagonally ordered silica nanocomposite fibers were used for the extraction of some polycyclic aromatic hydrocarbons from water samples. The extracted analytes were transferred to the injection port of a gas chromatograph using a laboratory-designed SPME device. The results obtained prove the ability of the polythiophene/hexagonally ordered silica material as a new fiber for the sampling of organic compounds from water samples. This behavior is due most probably to the increased surface area of the polythiophene/hexagonally ordered silica nanocomposite. A one-at-a-time optimization strategy was applied for optimizing the important extraction parameters such as extraction temperature, extraction time, ionic strength, stirring rate, and desorption temperature and time. Under the optimum conditions, the LOD of the proposed method is 0.1-3 pg/mL for analysis of polycyclic aromatic hydrocarbons from aqueous samples, and the calibration graphs were linear in a concentration range of 0.001-20 ng/mL (R(2) > 0.990) for most of the polycyclic aromatic hydrocarbons. The single fiber repeatability and fiber-to-fiber reproducibility were less than 8.6 and 19.1% (n = 5), respectively.

Keywords: GC-MS; Hexagonally ordered silica; Polycyclic aromatic hydrocarbons; Polythiophene; Solid-phase microextraction.