Selectivity Determination of Pb2+ Ion Based on TiO2-Ionophores BEK6 as Carbon Paste Electrode Composite

Pb2+ ion was investigated by voltammetry selectivity using TiO2-Ionophores hexa(p-tert butyl)hexa(ethyl ester)calix[6]arene (BEK6) composite to increase the selectivity and sensitivity of carbon paste electrode (CPE). The BEK6 was synthesized by using hydrolysis method, meanwhile the TiO2-P25 and graphite powder were mixed as an electrode composite. The Scanning Electron Microscopy (SEM) shows that the CPE doped TiO2-BEK6 (CPE/TiO2-BEK6) have morphology likes a rough, non-porous, composed of fine particles, and homogeneously. The presence of Pb2+ ion in pH 5 citrate buffer electrolyte causes the peaks appearance on Epa and Epc were 0.17 V and 0.37 V with  the peak potential current generated of 15.15 μA and -12.0 μA, respectively. The 0.005 g BEK6 was increased significantly the peak current of the Pb2+ ion with the LOD value of 0.1756. In addition, the presence of TiO2-BEK6 composite shows the measurement current stability by %RSD of 0.83.