Electrochemical sensor based on EDTA intercalated into layered double hydroxides of magnesium and aluminum for ultra trace level detection of lead (II)

The chelator ethylene diaminetetraacetate (EDTA) has been intercalated into layered double hydroxides by the anion exchange method. The resulting composites were characterized by powder X-ray diffraction, FTIR spectroscopy, thermogravimetry and X-ray photoelectron spectrometry. They were applied to modify a carbon paste electrode for the stripping voltammetric determination of lead (II) ions at ng L-1 levels. Stripping currents are linearly related to the logarithm of Pb (II) concentrations from 2 ng L-1 to 33 mu g L-1. The detection limit (3 sigma) is as low as 0.95 ng L-1. The method was successfully applied to the determination of Pb (II) in spiked tap water without any pretreatment.