New Pb2+ carbon paste electrode based on organically modified silicate and its square wave anodic stripping voltammetric response for pretreated gasoline samples

Abstract

An analytical procedure for determining Pb2+ by square wave anodic stripping voltammetry in pretreated gasoline sample is described and a carbon paste electrode modified with a inorganic-organic hybrid material (aminopropyl linked to the silica network (APSil) obtained by the sol-gel method) was evaluated as an electrochemical sensor. The optimum conditions for the analysis of Pb2+ ions were presented as follows: composition of APSil on the carbon paste electrode 40% (wt.%); deposition solution of pH 1.8; accumulation potential of-0.7 V vs. Ag/AgCl and deposition time of 600 s. Interference studies indicated that only Cu2+ at a 5-fold excess, interfered drastically on the stripping response of Pb2+. © 2010 Sociedade Brasileira de Química.