Solid-phase microextraction and ion chromatographic analysis of anions based on polypyrrole electrode

The polypyrrole (PPy) film was used for the selective extraction of trace levels of chloride, nitrite, and nitrate ions by solid phase micro-extraction (SPME). PPy film was electrochemically prepared from aqueous solutions of pyrrole and LiClO4 under N-2 atmosphere at constant potential of +0.80 V (versus Ag/AgCl). The anion uptake and release properties of the PPy film electrodes were examined under both open circuit and controlled potential conditions for prospective applications in electrochemically controlled solid-phase microextraction (EC-SPME). Applied positive and negative potentials facilitated the extraction and desorption of anions, respectively. Ions were desorbed into sample aliquot and were determined by ion chromatography (IC). The effect of uptake/release parameters, potential, time, pH of the uptake solution, on EC-SPME of anions was investigated. The method was validated using a standard reference material and tested for the determination of the ions in water samples. (C) 2008 Wiley Periodicals, Inc.