Preconcentration and determination of Pb2+ at an AlPO4 containing carbon paste electrode

In this paper, the analytical performance of a AlPO4 containing chemically modified electrode (CME) for Pb2+ preconcentration and quantitation will be discussed. The electrode employed was prepared simply by the addition of an appropriate quantity of sparingly soluble AlPO4 as a modifier to a conventional carbon paste mixture. This procedure yielded stable, reproducible CME surfaces which exhibited an efficient uptake of Pb2+, presumably as the even less soluble Pb3(PO4)2, in the presence of large excesses of Zn(II), Cd(II), Sn(II), Cu(II), Ag(I), and Ni(II). Detection at the sub-micromolar level was possible with a 5-min preconcentration. Uncertainties in the detected quantities were generally less than 5%.