Carbon Nanotube/Polypyrrole Composites as a Novel Solid Phase Microextraction Fiber Coating for the Preconcentration of n-Alkanes from Aqueous Media

Abstract

In this paper, the electrochemical fiber coating (EFC) technique was used for the preparation of oxidized multiwalled carbon nanotubes–polypyrrole composite (MWCNTs–PPy) and applied as a new fiber for solid-phase microextraction (SPME) procedures in the gas chromatographic (GC) determination of n-alkanes in aqueous samples. The effects of various parameters on the efficiency of SPME process such as extraction time, extraction temperature, ionic strength, stirring rate and desorption time were studied. Under optimized conditions, the linear dynamic range of developed SPME-GC for the selected n-alkanes spanned 0.5-500 ngmL⁻¹ with R² larger than 0.996 and the limits of detection (N= 3) were in the range of 0.010–0.050 ngmL⁻¹. The method displayed good repeatability by using a single fiber (RSD<2.14%) and good fiber-to fiber reproducibility (RSD<7.65%). All of these characteristics demonstrate that the proposed SPME is an efficient, flexible and versatile sampling and extraction tool which is ideally suited for use with chromatographic methods.

KEYWORDS: Solid-phase microextraction; n-Alkanes; Composite polymer; Carbon nanotube Polypyrrole.