A novel detection approach based on chromophore-decolorizing with free radical and application to photometric determination of copper with acid chrome dark blue.
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.
Gao
Hong-Wen
HW
Key Laboratory of Yangtze Water Environment of Ministry of Education, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China.
Chen
Fang-Fang
FF
Chen
Ling
L
Zeng
Teng
T
Pan
Lu-Ting
LT
Li
Jian-Hua
JH
Luo
Hua-Fei
HF
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
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