Trace detection of Ce3+ by adsorption strip voltammetry at a carbon paste electrode modified with ion imprinted polymers

To develop a convenient method for sensitive and selective determination of Ce³⁺ in aqueous phase with complicated matrices, a carbon paste electrode (CPE) modified with ion imprinted polymers (IIPs) were fabricated. The polymers were prepared by precipitation polymerization using Ce³⁺ as template, allyl phenoxyacetate (APA) as monomer, ethylene glycol dimethacrylate (EGDMA) as crosslinker and azobisisobutyronitrile (AIBN) as initiator under the molar ratio of Ce³⁺, APA and EGDMA as 1:4:40, respectively. Ce³⁺ was detected directly by differential pulse adsorptive stripping voltammetry (DPASV) and its oxidation peak appears at about 0.93 V. All parameters affecting the sensor's response are optimized and a calibration curve is plotted at a linear range of 1.0 × 10^?6–1.0 × 10^?5 mol/L and 1.0 × 10^?5–2.0 × 10^?4 mol/L with the detection limit of 1.5 × 10^?7 mol/L. All other rare earth ions have no interference with the determination of Ce³⁺ even at a concentration 500 times higher than that of Ce³⁺. This sensor was successfully applied to determination of Ce³⁺ in two catalyst sample solutions with RSD≤3.3% (n = 5) and recoveries in the range of 99.2%–106.5% at our optimal conditions.