title: A novel detection approach based on chromophore-decolorizing with free radical and application to photometric determination of copper with acid chrome dark blue.
abstract: A novel detection approach named chromophore-decolorizing with free radicals is developed for determination of trace heavy metal. The hydroxyl radicals (HO) generated from Fe(III) and hydrogen peroxide will oxidize the free chromophore into almost colorless products. The copper-acid chrome dark blue (ACDB) complexation was investigated at pH 5.07. In the presence of Fe(III) and hydrogen peroxide, the excess ACDB was decolorized in the Cu-ACDB reaction solution, and the final solution contained only one color compound, the Cu-ACDB complex. After oxidation of free hydroxyl radicals, the complexation becomes sensitive and selective and it has been used for the quantitation of trace amounts of Cu(II) dissolved in natural water. Beer's law is obeyed in the range from 0 to 0.500 microg mL(-1) Cu(II) and the limit of detection is only 6 microg L(-1) Cu(II). Besides, the Cu-ACDB complex formed was characterized.
authors: Key Laboratory of Yangtze Water Environment of Ministry of Education, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China.
authors: Hong-Wen
authors: HW
authors: Gao
authors: Fang-Fang
authors: FF
authors: Chen
authors: Ling
authors: L
authors: Chen
authors: Teng
authors: T
authors: Zeng
authors: Lu-Ting
authors: LT
authors: Pan
authors: Jian-Hua
authors: JH
authors: Li
authors: Hua-Fei
authors: HF
authors: Luo
mesh_terms: D001391:Azo Compounds / Q000737:chemistry*; D003300:Copper / Q000737:chemistry*; D004247:DNA / Q000737:chemistry; D004563:Electrochemistry / Q000379:methods*; D005609:Free Radicals / Q000737:chemistry; D006861:Hydrogen Peroxide / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D007202:Indicators and Reagents / Q000737:chemistry / Q000494:pharmacology*; D007501:Iron / Q000737:chemistry; D008956:Models, Chemical; D009282:Naphthalenesulfonates / Q000737:chemistry*; D010783:Photometry / Q000379:methods*; D012680:Sensitivity and Specificity; D013053:Spectrophotometry / Q000379:methods; D014131:Trace Elements / Q000737:chemistry
chemical_list: C520725:3-(2-hydroxyphenylazo)-4,5-dihydroxynaphthalene-2,7-disulfonic acid; D001391:Azo Compounds; D005609:Free Radicals; D007202:Indicators and Reagents; D009282:Naphthalenesulfonates; D014131:Trace Elements; D003300:Copper; D004247:DNA; D006861:Hydrogen Peroxide; D007501:Iron