Automated extraction and preconcentration of multiresidue of pesticides on a micro-solid-phase extraction system based on polypyrrole as sorbent and off-line monitoring by gas chromatography–flame ionization detection

A simple and efficient automated method for extraction and preconcentration of some organophosphorus and organochlorine pesticides from drinking and agriculture waters has been developed. In this work, a pyrrole-based polymer was synthesized and applied as an efficient sorbent for micro-solid-phase extraction (μ-SPE). Polypyrrole (PPY) was synthesized by chemical oxidation of the monomer in nonaqueous solution. The μ-SPE of selected pesticides, from aqueous samples was performed using 20 mg of PPY. After extraction, analytes were desorbed in ethyl acetate and analyzed using gas chromatography–flame ionization detection. The acid–base and other physico-chemical interactions with the analytes facilitated the adsorption of analytes, with good selectivity and reproducibility. Under the optimized extraction conditions, the method showed good linearity in the range of 0.001–0.3 μg ml−1 of water sample (phosphate buffer 1.0 × 10−3 M, pH 8.5), RSD = 1.5–4.2% (n = 4), and limits of detection 200–600 pg ml−1. Each μ-SPE cartridge could be used for up to 20 extractions.