Comparative effects of cyclodextrins nanocavities versus organic solvents on the fluorescence of carbamate and indole compounds

N. L. PACIONI; A.G. BRACAMONTE; A.V. VEGLIA

JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY

Elsevier

Lugar: Amsterdam; Año: 2008 vol. 198 p. 179 - 179

1010-6030

he effect of the addition of different amounts of organic solvents (S) on the fluorescence of aromatic compounds (C) and their inclusion complexes with -cyclodextrin (CD) and hydroxypropyl--cyclodextrin (HPCD) has been examined using steady-state measurements. Carbamate pesticides with different aromatic moiety, such as carbofuran (CF), promecarb (PC), carbaryl (CY) and bendiocarb (BC) were used, as well as indole derivatives with different polarity in their lateral chains, such as melatonin (M, neutral), 5-methoxytryptamine (MT, cation) and auxin (IA, anion). Their complexes in water show a fluorescence signal higher than that obtained for the free substrates in solvent:water mixtures (30%, v/v n-propanol or acetonitrile, and 50%, v/v methanol). The isofluorescent point (IF), the %IF and the F85% are defined in order to evaluate the use of CD nanocavities as a non-polluting alternative for the analysis of the compounds analyzed. Apparent formation constants (KAP, M−1) for the c