Sensitive and selective flow-injection analysis coupled with solvent-extraction for the determination of pharmaceuticals and environmental pollutants

Abstract

Sensitive and selective flow injection systems coupled with liquid-liquid extraction were proposed. Extraction/FI systems were applied to the determination of quaternary ammonium salts (R₄N⁺) in pharmaceuticals, anionic surfactant and dissolved oxygen in environmental water samples. A homemade thermo-controlled flow cell was used for the selective determination of cationic surfactants. Also, several kinds of phase separators were designed. Especially, a double-membrane phase separator gave efficient and constant separation with long-term continuous runs. Consequently, the proposed solvent-extraction/FIA systems are useful for the analyses of pharmaceuticals and environmental pollutants.