title: Postcolumn formation of fluorophores from nitrogenous pesticides by UV photolysis.
abstract: The ultraviolet (UV) photolysis of several classes of nitrogenous pesticides was examined with a view to photo-induced fluorescence detection in flow-injection analysis (FIA) and liquid chromatography. The solvents evaluated as typical reversed-phase mobile phases included water, methanol, and 1:1 mixtures of methanol/water and acetonitrile/water, and methanol/acetonitrilelwater mixtures. Acetone, acetophenone, the surfactant triton X-100, and the photocatalyst titanium dioxide were assessed as photosensitizers to enhance the UV photolysis and fluorescence responses. FIA and liquid chromatographic separations of several pesticides were followed by post-column UV photolysis for the fluorescence detection. Ultraviolet photolysis produces some fluorescent products. The type of photolytic solvent seems to play a significant role. The presence of photosensitizers also affects the fluorescence response of some pesticides. The photochemical transformation products of some of the pesticides are suggested. Analytical figures of merit were evaluated for determination of several pesticides in ground water. The post-column UV photolysis approach for fluorescence detection in liquid chromatography was assessed for several nitrogenous pesticides in ground water samples at ng/g concentrations.
authors.affiliation: Pesticide Research Laboratory, Food Science and Human Nutrition Department, University of Florida, Gainesville, FL 32611-0531, U.S.A.
authors.forename: B M
authors.initials: BM
authors.lastname: Patel
authors.forename: H A
authors.initials: HA
authors.lastname: Moye
authors.forename: R
authors.initials: R
authors.lastname: Weinberger