New design for the on-line solid-phase extraction of pesticides using membrane extraction disk material and liquid chromatography in environmental waters

摘要

A new design consisting of a microcoiumn (10 cm X 4.6 mm I.D.) filled with a spiral of C_(18) Empore disk material for the on-line trace enrichment of polar pesticides in environmental waters is described. The breakthrough volumes obtained were threetimes greater than those obtained using ten small Empore disks (4.6 mm I.D.) and were comparable to the ones obtained using the same dimensions of PRP-1 or PLRP-S precolumns. Samples were spiked with 0.1-1.0 μg l~(-1) of pesticides (in drinking, groundand sea water) and were preconcentrated using solid-phase extraction onto spiral C_(18) Empore disk material precolumns followed by liquid chromatography-diode array detection. This approach allowed the determination of all pesticides studied in water atthe concentration level required in Europe.