title: Nonaqueous catalytic fluorometric trace determination of vanadium based on the pyronine B-hydrogen peroxide reaction and flow injection after cloud point extraction.
abstract: The catalytic effect of vanadium on the pyronine B-H2O2 system is examined. Enhancement of the catalytic reaction rate along with the efficiency and selectivity against vanadium is achieved in a formic acid environment in the presence of a nonionic surfactant (Triton X-114). Elimination of drastic interference caused by inorganic acids and aqueous matrix along with a 50-fold preconcentration of vanadium are facilitated through cloud point extraction of its neutral complex with 8-quinolinol in an acidic solution. Subsequent flow injection analysis (FIA) with fluorometric detection renders the proposed method ideal for selective and cost-effective determination of as little as 0.020 microng L(-1) vanadium in environmental, biological, and food substrates. The preconcentration step can be applied simultaneously to multiple samples, allowing for massive preparation prior to analysis, compensating, thus, for the time-consuming procedure.
authors.affiliation: Department of Chemistry, University of Ioannina, Greece.
authors.forename: E K
authors.initials: EK
authors.lastname: Paleologos
authors.forename: M A
authors.initials: MA
authors.lastname: Koupparis
authors.forename: M I
authors.initials: MI
authors.lastname: Karayannis
authors.forename: P G
authors.initials: PG
authors.lastname: Veltsistas
mesh_terms: D002384:Catalysis; D019587:Dietary Supplements / Q000032:analysis; D005506:Food Contamination; D006197:Hair / Q000737:chemistry; D006801:Humans; D006861:Hydrogen Peroxide / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D015394:Molecular Structure; D017830:Octoxynol; D015125:Oxyquinoline / Q000737:chemistry; D011092:Polyethylene Glycols / Q000737:chemistry; D011754:Pyronine / Q000031:analogs & derivatives / Q000737:chemistry*; D013050:Spectrometry, Fluorescence / Q000379:methods*; D014639:Vanadium / Q000032:analysis*; D014867:Water / Q000032:analysis
chemical_list: D014639:Vanadium; D014867:Water; D011092:Polyethylene Glycols; D015125:Oxyquinoline; D017830:Octoxynol; C010615:Nonidet P-40; D006861:Hydrogen Peroxide; C012020:pyronine B; D011754:Pyronine