FLUOROMETRIC-DETERMINATION OF COPPER(II) BY ITS CATALYTIC EFFECT ON THE OXIDATION OF 1,10-PHENANTHROLINE WITH HYDROGEN-PEROXIDE

Catalytic analysis of copper(II) was investigated by measuring a highl y fluorescent 3,3'-diformyl-2,2'-dipyridyl formed in the copper(II) ca talyzed oxidation of 1,10-phenanthroline with hydrogen peroxide. There fore, copper(II) ion was determined indirectly by fluorometry. The rec ommended procedure is as follows: Take 10 ml of sample solution contai ning less than 0.3 mu g of copper ion. Add 2 ml of 7.5X10(-3) M 1,10-p henanthroline and 5 ml of 0.1 M Na2B4O7 buffer solution to the sample solution. Adjust the pH to 11.5 with sodium hydroxide solution. Add 1 ml of 11.5% hydrogen peroxide solution. Dilute the solution to 25 ml w ith distilled water. The pH of the resultant solution is adjusted to 1 0.4. Allow the solution to stand for 10 min at 40 degrees C. Measure t he fluorescence intensity of the final solution at 430 nm with an exci ting wavelength of 330 nm. The possible range of determination is from 0.02 to 0.25 mu g. The proposed method was applied to the determinati on of copper(II) in tap water. The results were in good agreement with determinations by flame-less AAS.