Kinerja Elektrode Pasta Karbon Termodifikasi Nanomagnetit pada Teknik Voltametri Siklik

Abstract

The performance of nanomagnetite-modified carbon paste electrodes (CPE) are influenced by the characteristics of nanomagnetite. This study determined the performance of a CPE modified with nanomagnetite synthesized by hydrothermal technique from FeCl3, urea, and sodium citrate at 200 °C for 3 hours. The electrode performance was determined by cyclic voltammetry technique by using iodide as analyte in KCl as supporting electrolyte at potential range of 0.0 to 1.2 V. Voltammetric analysis provided two pairs of oxidation and reduction peaks, both of them quasireversible. Nanomagnetite improved the response of iodide oxidation peak current 1.4 fold compared with the unmodified CPE. The electrode sensitivity was 16.04 mA/mM, the detection limit was 0.0462 mM, and the quantitation limit was 0.154 mM. The electrode selectivity was still good until 10- times addition of interference ion. The linearity of correlation of iodide concentration with oxidation peak current was good as well. However the electrode current response decreased after being stored for a month. Overall, the electrode performances were not as good as CPE modified with nanomagnetite synthesized for 12 hours previously reported