title: Study on the mechanism and applications of the fluorescence reactions among cobalt (II), H(2)O(2) and two new derivatives of 8-sulfonamidoquinoline.
abstract: The fluorescence intensities of the reaction systems of Co(II) with two new 8-sulfonamidoquinoline derivatives, 5-(4-Chlorophenylazo)-8-(benzenesulfonamido)-quinoline (CPBSQ), which was firstly synthesized and characterized, and 5-(3-fluo-4-chlorophenylazo)-8-(benzenesulfonamido)quinoline (FCPBSQ), could be enhanced by H(2)O(2). The mechanism and analytical characters of these reactions in the presence of H(2)O(2) were investigated in this paper. CPBSQ and FCPBSQ reacted with Co(II) in the presence of H(2)O(2) and in the basic medium forming a chelate, which exhibited an intensive fluorescence in ultraviolet region. The fluorescence intensities were proportional to the concentration of Co(II) over the range of 0.1-100 and 0.5-200 mug/l with the detection limits of 0.05 and 0.10 mug/l for the CPBSQ and FCPBSQ systems, respectively. A lot of metal ions included Cu(II) and Ni(II) did not interfere the determinations for both the systems. The methods, which are high sensitive and more selective, have been successfully applied to the determination of trace amount of cobalt in environmental and biological samples.
authors.affiliation: Department of Chemistry, Lanzhou University, Lanzhou 730000, PR China; Department of Chemistry, Yunnan University, Kunmin 650091, PR China.
authors.forename: Q E
authors.initials: QE
authors.lastname: Cao
authors.forename: Y
authors.initials: Y
authors.lastname: Zhao
authors.forename: S
authors.initials: S
authors.lastname: Wu
authors.forename: Z
authors.initials: Z
authors.lastname: Hu
authors.forename: Q
authors.initials: Q
authors.lastname: Xu