Static–dynamic pressurized hot water extraction coupled to on-line filtration–solid-phase extraction–high-performance liquid chromatography–post-column derivatization–fluorescence detection for the analysis of N-methylcarbamates in foods

Abstract

A combination of static–dynamic modes of pressurized hot water extraction has been used for the extraction of N-methylcarbamates (namely, oxamyl, dioxacarb, metholcarb, carbofuran and carbaryl) from different fruits and vegetables. The selection of water as leaching agent provides a clean approach which avoids the use of organic solvents. A flow injection manifold coupled to the extractor has allowed the automation of the subsequent steps (namely, filtration, preconcentration, individual chromatographic separation, post-column derivatization and fluorescence detection) involved in the analytical process. Good recoveries, ranging from 80 to 104%, and precision, expressed as relative standard deviation, between 3.0 and 8.4% have been achieved by the proposed method.