DETERMINATION OF HG-II ION WITH A 11-BIS(8-QUINOYLOXY)-3,6,9-TRIOXAUNDECANE-MODIFIED GLASSY-CARBON ELECTRODE USING SPIN-COATING TECHNIQUE

A glassy carbon electrode modified with an open-chain crown ether, 1,1 1-bis(s-quinolyloxy)-3,6,9-trioxaundecane (BQT), using a spin coating method, has been applied for the highly selective and sensitive analys is of trace amounts of Hg-II. The modified electrode Hg-II ion was spo ntaneously deposited on the modified electrode and the resulting surfa ces were characterized by anodic stripping voltammetry. The linear swe ep voltammogram of the modified electrode deposited with Hg-II ion sho ws a well-defined anodic peak at +0.17V. The detection limit with line ar sweep voltammetry was 1.0 x 10(-8) M and was about 7.0 x 10(-10) M Hg-II by differential pulse anodic voltammetry. The response reproduce d with a value of 6.1% relative standard deviation. The presence of 20 -fold molar Ag-I, Cd-II, Pb-II, Fe-II, Ni-II, Co-II, Cu-II, Al-III, Mg -II, Sb-III, Ti-II, and Zn-II did not interfere in the analysis of Hg- II ion except Fe-II. The electrode has been successfully applied to th e determination of trace amounts of the Hg-II ion in the human urine s ample.