A novel fully automated effervescence-assisted switchable solvent-based liquid phase microextraction procedure has been suggested. In this extraction method, medium-chain saturated fatty acids were investigated as switchable hydrophilicity solvents. The conversion of fatty acid into hydrophilic form was carried out in the presence of sodium carbonate. The injection of sulfuric acid into the solution decreased the pH value of the solution, thus, microdroplets of the fatty acid were generated. Carbon dioxide bubbles were generated in-situ, and promoted the extraction process and final phase separation. The performance of the suggested approach was demonstrated by the determination of ofloxacin in human urine samples using high-performance liquid chromatography with fluorescence detection. This analytical task was used as a proof-of-concept example. Under the optimal conditions, the detector response of ofloxacin was linear in the concentration ranges of 3·10(-8)-3·10(-6) mol L(-1). The limit of detection, calculated from a blank test based on 3σ, was 1·10(-8) mol L(-1). The results demonstrated that the presented approach is highly cost-effective, simple, rapid and environmentally friendly.
Keywords: Effervescence-assisted switchable solvent-based liquid phase microextraction; Fatty acids; Flow analysis; Green analytical chemistry; Ofloxacin; Urine.
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