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+.
inorganic-organic hybrid; lead determination; stripping voltammetry; carbon paste electrode
