Assessment of Ethyl Carbamate Contamination in Cachaça (Brazilian Sugar Cane Spirit)

A facile synthesis of molecularly imprinted polymers and their properties as electrochemical sensors for ethyl carbamate analysis

New molecularly imprinted polymers (MIPs), which exhibit specific recognition of ethyl carbamate (EC) have been synthesized and studied. In this process, EC was the template molecule and β-cyclodextrin derivatives were employed as functional monomers in the molecular imprinting technique (MIT). An EC molecularly imprinted sensor (EC-MIS) was prepared by using MIT surface modification. The EC-MIS was characterized by cyclic voltammetry, electrochemical impedance spectroscopy and differential pulse voltammetry. EC detection performance, binding parameters and dynamics mechanism were investigated. The result showed that the synthetic route designed was appropriate and that new MIP and EC-MIS were successfully prepared. The EC-MIS exhibited a good molecular recognition of EC. A linear relationship between current and EC concentration was observed using cyclic voltammetry and the detection limit was 5.86 μg L⁻¹. The binding constant (K = 4.75 × 10⁶ L mol⁻¹) between EC and the EC-MIS, as well as, the number of binding sites (n = 1.48) has been determined. The EC-MIS recognition mechanism for the EC is a two-step process. The sensor was applied for the determination of EC in Chinese yellow wines, and the results were in good agreement with the gas chromatography-mass spectrometry (GC-MS) method.

An ethyl carbamate (EC) molecularly imprinted sensor (EC-MIS) has been prepared. The molecular recognition properties of EC were investigated, the binding parameters determined, and the dynamic mechanism of EC-MIS recognizing EC explored.