Microextraction of phenolic compounds using a fiber coated with a polyaniline-montmorillonite nanocomposite

A highly porous fiber coated polyaniline/montmorillonite clay was prepared for solid-phase microextraction. The nanocomposite was synthesized by in-situ polymerization. The resulting material was characterized by scanning electron microscopy, UV-Vis and FT-IR spectroscopy. The prepared nanomaterial was immobilized on a stainless steel wire for fabrication of the solid-phase microextraction fiber. The fiber was evaluated for the extraction of some phenolic compounds from aqueous sample solutions in combination with gas chromatography-mass spectrometry. A one at-the-time strategy was applied for optimizing extraction temperature, extraction time, ionic strength, pH, stirring rate, desorption time and desorption temperature. Under optimum conditions, the repeatability for one fiber (n = 3), expressed as relative standard deviation (R.S.D. %), was between 4.6 and 9.1 %. The quantitation limit for the studied compounds was between 5 and 14 pg mL(-1). The developed method offers the advantage of being simple to use, with shorter analysis times, lower cost of equipment, thermal stability of fiber and high relative recovery in comparison to conventional methods of analysis.