Application of cellulose sponge modified by polypyrrole for thin film microextraction of polycyclic aromatic hydrocarbons.

In this work, a flexible and environmentally compatible thin film, consisted of cellulose and polypyrrole, was prepared and used as a new thin film microextraction sorbent for adsorption and determination of trace amount of methylnaphthalene, anthracene and pyrene from aqueous samples. Analytes were determined by gas chromatography equipped with a flame ionization detector. polypyrrole was used as a modifier due to its porous structure and good mechanical stability in aqueous solution. Pyrrole monomers deposited on cellulosic substrate were polymerized through oxidative chemical polymerization. Extraction of analytes from sample solution to the cellulose/poly pyrrole film was performed through π-π interactions between the sorbent and polycyclic aromatic hydrocarbons (PAHs). Extraction efficiency was studied by changing parameters such as desorption solvent, time of desorption, volume of desorption solvent, salt concentration, temperature and extraction time were optimized. The detection limits of 1.40, 0.60 and 0.45 µg L-1 were obtained for methylnaphthalene, anthracene and pyrene, respectively. The method showed good linearity in the concentration range of 4-3000, 2-1000, and 1-500 µg L-1 for methylnaphthalene, anthracene and pyrene, respectively. Intra- and inter-day precision were in the range of 6.0-8.0% and 12.0-15.0%, respectively. Finally, PAHs were determined in real samples by this method. Recovery for real samples was in the range of 53-102%.