Reversed-phase liquid chromatographic column switching for the determination of N-methylcarbamates and some of their main metabolites in urine

A column switching system for the determination of some polar pesticides an d their main metabolites, such as aldicarb, aldicarb sulphoxide, aldicarb s ulphone, carbofuran and 3-hydroxicarbofuran, in human urine has been develo ped, The limits of detection were between 0.3 and 1 mu g/l. We used a simpl e solid-phase extraction with graphite carbon and a RPLC-LC analysis with U V detection yielding average recoveries between 84 and 110% (N=5) with RSD between 4 and 8%. (C) 2000 Elsevier Science B.V. All rights reserved.