Hydroxypropyl-B-cyclodextrin effect on the fluorescence of auxin and skatole and on the simultaneous determination of binary mixtures of indole compounds in urine by first derivative spectrofluorimetry

R. E. GALIAN; A. G. BRACAMONTE ; A. V. VEGLIA

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2005 vol. 540 p. 393 - 393

he effect of hydroxypropyl--cyclodextrin (HPCD, -cyclodextrin (CD) derivative) was determined on the fluorescence emissionspectra of skatole (3-methylindole, MI) and auxin (indole 3-acetic acid, IA). The experiments were conducted at excitation wavelength(λex) = 280 nm, in aqueous solutions at different pH values, with and without HPCD as receptor. The enhanced fluorescence in the presenceof the receptor showed a 1:1 host?guest interaction and the values of the association constants KA were between 100 and 200 mol−1 L. Theeffects of methanol and propanol with and without receptor were also studied. The limit of detection (LD) for the HPCD enhanced fluorimetricmethod at pH = 7.00 were 0.279 and 0.765 ngmL−1 for MI and IA, respectively. For the determination of indole compounds with closelyoverlapping spectral bands a zero-crossing first derivative spectrofluorimetric method with or without HPCD is described. Binary mixturesof M