Automated determination of Vinclozolin at the ppb level in aqueous samples by a combination of microporous membrane liquid-liquid extraction and adsorption chromatography

An automated system with microporous membrane liquid-liquid extraction (MMLLE) combined with HPLC has been designed for the determination of Vinclozolin in aqueous matrices. In MMLLE a porous hydrophobic membrane separates an aqueous phase from an organic phase. The pores are filled with the organic solvent. In this work, MMLLE was performed in a flow system and coupled on-line to normal phase HPLC. The performance of the system was evaluated with respect to enrichment when processing large sample volumes. Enrichment factors of 118 times were obtained and the limit of detection was around 1 ng/ml. This technique is an alternative to classical LLE and offers advantages such as reduced solvent consumption, possibility of automation and avoidance of emulsion formations. (C) 2000 Elsevier Science B.V. All rights reserved.