Construction of a New Molecular Imprinted Carbon Paste Electrode for Selective Determination of Ethyl Carbamate

Zohreh Baroon Poura¹ Javad Tashkhourian²

1) Shiraz University:
2) Shiraz University:

Publication : 13th Biennial Electrochemistry Seminar of Iran(elect13pguac.ir)
Abstract :
Ethyl carbamate (EC) , known as urethane, is an ethyl ester of carbamic acid and has been recognized as a well-known multi-site carcinogenic compound, causing the incidence of cancer especially in lung, blood vessels and liver based on animal experiments [1]. Genotoxic and carcinogenic effects have been confirmed in many species including rats, mice, hamsters and monkeys [2]. National Toxicology Program (NTP) revealed the probable carcinogenicity of EC to humans. It is naturally formed in fermented foods during fermentation process and/or during storage. Furthermore, EC has been detected in various fermented products such as bread, yoghurt, cheese, soy sauce, and vinegar [3]. The previous investigation have indicated that EC production is due to the natural biochemical processes e. g reaction of ethanol and nitrogen-containing compounds, such as urea, carbamyl phosphate and cyanide [4].There are different methods to the detection of EC but more of them are based HPLC technique that is expensive and time consuming. It is crucial to present a new cost effective and simple method to EC detection. Molecular imprinting is a simple and well established methodology to prepare materials with recognition sites for specific molecules that is pioneered more than thirty years ago [5].The MIP material acted as a recognition element of the sensor and can be used for specific recognition of target molecules owing to the binding sites complementary in size and shape to the templates. In electrochemical sensors, MIPs cannot only accumulate template molecules on the electrode surface to enhance the sensitivity, but also separate template molecules from the other analytes to improve the selectivity. In this work, carbon-paste electrodes (CPE) modified with MIP was used for the sensitive electrochemical determination of Ethyl carbamate (EC). The electrodes are prepared by mixing a graphite powder, paraffin oil, and distinct amount of MIP powder, which was synthesized previously. The electrochemical response characteristics of these modified electrodes toward EC were investigated by cyclic voltammetry and square wave Voltammetry. Prior to established detection method, experimental parameters were optimized. The optimization time was 20 min and pH was 5.The changes in current before and after analyte loading recorded and used as analytical response. The sensor showed a good linear response in phosphate buffer pH=5 toward EC in the range of 1-500M with with LOD 0.01M and RSD 3.2%. Our result is comparable with previous researches that reported by Ming Guo in 2018, Xiaoyu Zhao in 2017 and Zhiwei Zhang in 2016. They represented the methods based on MIP and enzyme which indicated a linear range of 100 to 1300 nM, 100 to 1300 nM, 0.5 to 40M, respectively. For these works, the reported LOD were 0.065M, 37 nM and 5.30 nM, respectively.
Keywords : Ethyl carbamate molecularly imprinted polymers modified carbon-paste electrode electrochemical determination