Cucurbit[6]uril nanocavity as enhanced spectrofluorimetric method for the determination of pyrene.

V. N. SUELDO OCCELLO ; A. V. VEGLIA

ANALYTICA CHIMICA ACTA

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2011 vol. 689 p. 97 - 102

0003-2670

The effect of the addition of macrocyclic host cucurbit[6]uril (CB6) on the photophysical properties of polycyclic aromatic hydrocarbon pyrene (PYR) was analyzed. The fluorescence emission spectra of the aromatic compound were   determined at 25.0 ºC in different acidic media (HCl 18 % w/v or HCOOH 55 % w/v) with and without CB6. A significant enhancement in the fluorescence signals in the presence of CB6 was observed. The average values of the association constant (KA) for the 1:1 stoichiometry complex and the relative fluorescence quantum yield ratio between the complexed and free PYR (f PYR-CB6/f PYR) in acidic media were (4.0 ± 0.5) ´ 102 M-1 and (5.7 ± 0.2), respectively. The analytical parameters improved in the presence of CB6. The relative decrease in the limit of detection was 92 %. The matrix effect was evaluated in fortified samples of tap water and tea extracts. Apparent recoveries obtained by the proposed method in tap water and tea extracts were (82-103) % and (89-99) %, respectively. Selectivity studies with inorganic and organic species were performed. The method is rapid, direct, selective and simple.