Determination of trace amounts of zearalenone in beverage samples with an electrochemical sensor

A simple and sensitive electrochemical sensor is purposed for the preconcentration and determination of zearalenone using a carbon paste electrode modified with multi-walled carbon nanotubes. A differential pulse voltammetric method is employed to study the behavior of zearalenone on this modified electrode. The analytical procedure consists of a closed-circuit accumulation step onto the modified electrode. An anodic peak, related to the oxidation of accumulated and reduced zearalenone on the electrode surface, was observed at 0.40 V. The calibration curve was linear in the range of 2.0-50.0 ng mL(-1). The limit of detection was found to be 0.58 ng mL(-1), and the relative standard deviations for five replicated determinations at 5.0 and 30.0 ng mL(-1) of zearalenone were 2.71 and 1.44 %, respectively. The modified electrode was applied successfully for the analysis of zearalenone in different malt beverage samples.