title: Quantum dots assisted photocatalysis for the chemiluminometric determination of chemical oxygen demand using a single interface flow system.
abstract: A novel flow method for the determination of chemical oxygen demand (COD) is proposed in this work. It relies on the combination of a fully automated single interface flow system, an on-line UV photocatalytic unit and quantum dot (QD) nanotechnology. The developed approach takes advantage of CdTe nanocrystals capacity to generate strong oxidizing species upon irradiation with UV light, which fostered a fast catalytic degradation of the organic compounds. Luminol was used as a chemiluminescence (CL) probe for indirect COD assessment, since it is easily oxidized by the QD generated species yielding a strong CL emission that is quenched in the presence of the organic matter. The proposed methodology allowed the determination of COD concentrations between 1 and 35 mg L(-1), with good precision (R.S.D.<1.1%, n=3) and a sampling frequency of about 33 h(-1). The procedure was applied to the determination of COD in wastewater certified reference materials and the obtained results showed an excellent agreement with the certified values.
authors.affiliation: Requimte, Department of Chemistry, Faculty of Pharmacy, Porto University, Portugal.
authors.forename: Cristina I C
authors.initials: CI
authors.lastname: Silvestre
authors.forename: Christian
authors.initials: C
authors.lastname: Frigerio
authors.forename: João L M
authors.initials: JL
authors.lastname: Santos
authors.forename: José L F C
authors.initials: JL
authors.lastname: Lima
mesh_terms: D057919:Biological Oxygen Demand Analysis / Q000379:methods*; D002384:Catalysis; D004492:Edetic Acid / Q000737:chemistry; D008163:Luminescent Measurements / Q000295:instrumentation / Q000379:methods*; D008165:Luminol / Q000737:chemistry; D010100:Oxygen / Q000032:analysis*; D045663:Quantum Dots; D014466:Ultraviolet Rays
chemical_list: D008165:Luminol; D004492:Edetic Acid; D010100:Oxygen