The supramolecular interaction of dequalinium chloride (DQC) and -cyclodextrin has been studied by flow injection spectrofluorimetry. The results showed that -CD reacted with DQC to form a 1:1 host:guest complex with an apparent association constant of 4.99×102Lmol−1. Based on the enhancement of the fluorescence intensity of DQC, a flow injection sepctrofluoremetric method for the determination of DQC in bulk aqueous solution in the presence of -CD was developed. The linear range was 0.0412-30.00gmL−1. The detection limit was 12.3ngmL−1 with a sampling rate of 80h−1. There was no interference from the excipients normally used in tablets and serum compositions. The proposed method was successfully applied to the determination of DQC in tablets and serum.

A flow injection (FI) kinetic spectrofluorimetric method was developed for the determination of palladium and the possible mechanism of catalytic reaction was discussed. Salicylaldehyde furfuralhydrazone (SAFH) was newly synthesized and its ionization, IR and elemental analysis were established. The methodwas based on the fluorescent enhancing reaction of SAFH with potassium bromate, whichwas catalysed by palladium in water medium at pH 7.30 and 30℃. Under these experimental conditions, the oxidized product of SAFH had excitation and emission wavelengths maxima at 370 and 460nm, respectively. The linear range of this method was 1.0-210ng/ml−1 with the R.S.D. of 1.3% from a series of 11 standards each containing 50ng/ml−1 of palladium. The detection limit was 0.30ng/ml−1 of palladium. A high analysis rate of 24 samples h−1 was obtained by the FI method. Sensitivity and selectivity were increased by a Pd2+preconcentration separation methodology. The proposed method was applied successfully to determine palladium in synthetic mixtures and mineral samples, the common interference ions were separated, and the results were agreeable with the standard values.

A flow injection (FI) kinetic spectrofluorimetric method is described for the determination of osmium (IV) and the possible mechanism of catalytic reaction is discussed. The method is based on the fluorescence enhancing reaction of o-vanillin furfuralhydrazone (OVFH) with potassium bromate, which is catalyzed by Os (IV) in water medium at pH 6.10 and 45℃. OVFH is newly synthesized and its ionization, IR and elemental analysis are established. Under these experimental conditions, the oxidized product of OVFH has excitation and emission maxima at 337 and 490 nm, respectively. The linear range of this method is 0-600ng/ml−1 with the R.S.D. of 1.2%. The detection limit is 1.0ng ml−1 of Os (IV). A high analysis rate of 24 samples h−1 is obtained by the FI method. The proposed method is applied successfully to determine Os (IV) in synthetic mixture and mineral samples, and the results are well consistent with the standard values.

0 and 55℃. Under optimum conditions, beta-CD-osmium (IV)-KBrO3-OVFH supramolecular kinetic catalytic reaction system had excitation and emission maxima at 337 and 490 nm, respectively. The linear range of this method was 0-120ng/ml−1 with a R.S.D. of 1.1%, and the detection limit was 0.38ng/ml−1. The effect of interferences was studied. Distillation was used to separate osmium from interfering elements in the samples. The proposed method was applied successfully to determine osmium(IV) in synthetic mixture and mineral samples, the results were well consistent with the reference standard values.

This paper presents an automatic spectrofluorimetric method (flow injection analysis spectrofluorimetry) for detecting hydroxyl radicals. Based on H2O2 catalyzed by Co2+yielding HO•, the method utilized sodium terephthalate to trap hydroxyl radicals and obtained sodium 2-hydroxyterephthalate by aromatic hydroxylation, which resulted in an increase in the fluorescence intensity. The relative fluorescence intensity was proportional to the concentration of hydroxyl radicals. Hydroxyl radicals could be determined indirectly, based on the increase of fluorescence. It was a simple, rapid, precise, sensitive and automatic technique for the determination of HO•. The relative standard deviation of 11 determinations was 0.57%. The method can be used to sieve antioxidant medicines and will have theoretical and practical guidance on the mechanism of hydroxyl radicals-damaging biology.