Author(s): Gil Eric de S. | Kubota Lauro T.
Journal: Journal of the Brazilian Chemical Society
ISSN 0103-5053
Volume: 11;
Issue: 3;
Start page: 304;
Date: 2000;
Original page
Keywords: rhodium acetamidate | electrochemical sensors | hydrazine determination | carbon paste electrode | polyethylenimine
ABSTRACT
The electrochemical behavior of rhodium acetamidate immobilized in carbon paste electrode and the consequences for sensor construction were evaluated. The electrode showed good stability and redox properties. Two reversible redox couples with midpoint potentials between 0.15 and 0.55 V vs SCE were observed. However, peak resolution in voltammetric studies was very dependent on the supporting electrolyte. The correlation between coordinating power of the electrolyte and peak potential suggests that the electrolyte can coordinate through the axial position of the complexes. Furthermore, the axial position may be also the catalytic site, as a catalytical response was observed for hydrazine oxidation. A good linear response range for hydrazine was fit by the equation i = 23.13 (± 0.34) c , where i = current in mA and c = concentration in mol dm-3 in the range of 10-5 up to 10-2 mol dm-3. The low applied potential (
Journal: Journal of the Brazilian Chemical Society
ISSN 0103-5053
Volume: 11;
Issue: 3;
Start page: 304;
Date: 2000;
Original page
Keywords: rhodium acetamidate | electrochemical sensors | hydrazine determination | carbon paste electrode | polyethylenimine
ABSTRACT
The electrochemical behavior of rhodium acetamidate immobilized in carbon paste electrode and the consequences for sensor construction were evaluated. The electrode showed good stability and redox properties. Two reversible redox couples with midpoint potentials between 0.15 and 0.55 V vs SCE were observed. However, peak resolution in voltammetric studies was very dependent on the supporting electrolyte. The correlation between coordinating power of the electrolyte and peak potential suggests that the electrolyte can coordinate through the axial position of the complexes. Furthermore, the axial position may be also the catalytic site, as a catalytical response was observed for hydrazine oxidation. A good linear response range for hydrazine was fit by the equation i = 23.13 (± 0.34) c , where i = current in mA and c = concentration in mol dm-3 in the range of 10-5 up to 10-2 mol dm-3. The low applied potential (
