[Fluorimetric study of Tb-EDTA-quercetin and determination of quercetin]

Tb-EDTA-Quercetin complexes were formed under basic conditions. Intramolecular energy transfer occurs in the Tb-EDTA complex with quercetin (QCT) and the terbium (III) ion fluorescence can be sensitized by QCT. Accordingly a fluorimetric method was used for the determination of QCT in urine, serum and mixed substance of rutin-quercetin. The method is simple, sensitive and fast. The linear range is 5.0 x (-7)-1.0 x10(-5) mol x L(-1) and the detection limit is 5.0 x 10(-8) mol x L(-1). This method can be applied to the determination of QCT in non-pretreated urine and serum successfully. The recoveries are in the range of 103%-96%.