A Cubic Silsesquioxane Modified With Purpald?: Preparation, Characterization and a Voltammetric Application for Determination of Sulfite

摘要

A novel composite formed by interaction of a octa(3-chloropropyl)octasilsesquioxane modified with Purpald , and its subsequent reaction with silver and hexacyanoferrate (III) (AgHSP), wassynthesized and initially characterized by Fourier transform infrared spectra (FTIR) and cyclicvoltammetry. The cyclic voltammogram of the modified graphite paste electrode with AgHSP, showed-1 -1 one redox couple with formal potential E =0.64V (vs Ag/AgCl, KNO3, 1.0 mol L ; v = 20 mV s ),2+ 3+ attributed to the Fe (CN)6/ Fe (CN)6 process. The redox couple presents an electrocatalytic response-5 -3 for determination of sulfite. The modified electrode showed a linear response from 7.010 to 1.010-1 3 mol L with the corresponding equation Y(A) = 18.05 + 29.98310 [sulfite], and a correlation-4 -1 coefficient of r=0.999. The method showed a detection limit of 0.11510 mol L with a relative-3 -1 standard deviation of 4% (n = 3) and amperometric sensitivity of 29.98310 A mol L . Themodified electrode showed a excellent stability and good reproducibility during experiments.