Developments in liquid-phase microextraction

The development of faster, simpler, inexpensive and more environmentally friendly sample-p reparation techniques is an important issue in chemical analysis. Recent research trends involve miniaturisation of the traditional liquid-liquid extraction (LLE) principle by greatly reducing the acceptor-to-donor phase ratio. One of the emerging techniques in this area is liquid-phase microextraction (LPME), where a hollow fibre impregnated with an organic solvent is used to accommodate or protect microvolumes of acceptor solution. This novel methodology proved to be an extremely simple, low-cost and virtually solvent-free sample-preparation technique, which provided a high degree of selectivity and enrichment by additionally eliminating the possibility of carry-over between runs. This article presents the different modes and hollow-fibre configurations of LPME, followed by an up-to-date summary of its applications. The most important parameters and practical considerations for method optimisation are also discussed. The article concludes with a comparison of this novel method with solid-phase microextraction (SPME) and single-drop microextraction (SDME). (C) 2003 Published by Elsevier B.V.