title: Automatic flow analysis method to determine traces of Mn²⁺ in sea and drinking waters by a kinetic catalytic process using LWCC-spectrophotometric detection.
abstract: A new automatic kinetic catalytic method has been developed for the measurement of Mn(2+) in drinking and seawater samples. The method is based on the catalytic effect of Mn(2+) on the oxidation of tiron by hydrogen peroxide in presence of Pb(2+) as an activator. The optimum conditions were obtained at pH 10 with 0.019 mol L(-1) 2'2 bipyridyl, 0.005 mol L(-1) tiron and 0.38 mol L(-1) hydrogen peroxide. Flow system is based on multisyringe flow injection analysis (MSFIA) coupled with a lab-on-valve (LOV) device exploiting on line spectrophotometric detection by a Liquid Waveguide Capillary Cell (LWCC), 1m optical length and performed at 445 nm. Under the optimized conditions by a multivariate approach, the method allowed the measurement of Mn(2+) in a range of 0.03-35 µg L(-1) with a detection limit of 0.010 µg L(-1), attaining a repeatability of 1.4% RSD. The method was satisfactorily applied to the determination of Mn(2+) in environmental water samples. The reliability of method was also verified by determining the manganese content of the certified standard reference seawater sample, CASS-4.
authors.affiliation: Environment and Energy Department, Advanced Materials Research Center (CIMAV), Miguel de Cervantes 120, Chihuahua Chih, 31136, Mexico; Department of Chemistry, University of the Balearic Islands, Cra.Valldemossa Km 7.5, E-07122 Palma de Mallorca, Spain.
authors.forename: Laura
authors.initials: L
authors.lastname: Chaparro
authors.affiliation: Department of Chemistry, University of the Balearic Islands, Cra.Valldemossa Km 7.5, E-07122 Palma de Mallorca, Spain.
authors.forename: Laura
authors.initials: L
authors.lastname: Ferrer
authors.affiliation: Environment and Energy Department, Advanced Materials Research Center (CIMAV), Miguel de Cervantes 120, Chihuahua Chih, 31136, Mexico. Electronic address: luz.leal@cimav.edu.mx.
authors.forename: Luz O
authors.initials: LO
authors.lastname: Leal
authors.affiliation: Department of Chemistry, University of the Balearic Islands, Cra.Valldemossa Km 7.5, E-07122 Palma de Mallorca, Spain.
authors.forename: Víctor
authors.initials: V
authors.lastname: Cerdà
mesh_terms: D002384:Catalysis; D060766:Drinking Water / Q000032:analysis*; D019075:Electrophoresis, Capillary / Q000295:instrumentation / Q000379:methods; D017022:Flow Injection Analysis / Q000295:instrumentation / Q000379:methods; D057230:Limit of Detection; D008345:Manganese / Q000032:analysis*; D012623:Seawater / Q000032:analysis*
chemical_list: D060766:Drinking Water; D008345:Manganese
keywords: Kinetic-catalytic method; MSFIA-LOV system; Mn(2+) determination; Sea water; Tiron