Sensitive and rapid flow injection analysis of sulfonylurea herbicides in water with micellar-enhanced photochemically induced fluorescence detection

A flow injection analysis (FIA) system, combined with micellar-enhanced photochemically induced fluorescence (MEPIF) detection is developed for the sensitive and rapid determination of four sulfonylurea herbicides including chlorsulfuron, metsulfuron methyl, 3-rimsulfuron and sulfometuron methyl in water. The use of micellar solutions of sodium dodecyl sulfate (SDS) and cetyltrimethylammonium chloride (CTAC) as mobile phase provides improved analytical conditions. The FIA manifold parameters, viz, injection volume, flow rate and reactor length were optimized. Calibration plots were linear over 1-2 orders of magnitude. Relative standard deviation ranged from 1.5% to 3.7%. Limits of detection (LOD) were comprised between 0.1 and 1 ng ml(-1) according to the compound. The sample throughput was between 56 and 80 h(-1). Examples of application to the analysis of these herbicides in spiked river water are given. The mean recoveries ranged from 90% to 106%. (C) 1999 Elsevier Science B.V. All rights reserved.