Usefulness of micellar media for the quantitative analysis of phenylurea herbicides in water by photochemically-induced fluorescence

UV irradiation of four non-fluorescent phenylurea herbicides including linu ron, diuron, isoproturon and neburon is shown to yield fluorescent photopro ducts. The photochemically-induced fluorescence (PIF) properties of these h erbicides in several media (water. 2-propanol and their mixtures) and aqueo us micellar solutions of sodium dodecyl sulfate (SDS), and cetyltrimethylam monium chloride (CTAC) are reported. The use of micellar media enhances sig nificantly the PIF signal relative to an aqueous solution. A PIF method is developed for the determination of the four herbicides under study, with li near dynamic ranges over about one order of magnitude, and limits of detect ion (LOD) between 410 and 640 ng mL(-1), according to the compound. Applica tions to the analysis of tap water and river water samples yield satisfacto ry recoveries (86-115%).