Electrochemical detection of 4(5)-methylimidazole in aqueous solutions

Akhtar Bayat; Jesse Smiles Dondapati; Syed Rahin Ahmed; Seshasai Srinivasan; Amin Reza Rajabzadeh

doi:10.1016/j.foodchem.2024.139320

Electrochemical detection of 4(5)-methylimidazole in aqueous solutions

Food Chem. 2024 Apr 9:450:139320. doi: 10.1016/j.foodchem.2024.139320. Online ahead of print.

Authors

Akhtar Bayat¹, Jesse Smiles Dondapati¹, Syed Rahin Ahmed¹, Seshasai Srinivasan², Amin Reza Rajabzadeh³

Affiliations

¹ W. Booth School of Engineering Practice & Technology, McMaster University, Hamilton, Ontario L8S 4L8, Canada.
² W. Booth School of Engineering Practice & Technology, McMaster University, Hamilton, Ontario L8S 4L8, Canada. Electronic address: ssriniv@mcmaster.ca.
³ W. Booth School of Engineering Practice & Technology, McMaster University, Hamilton, Ontario L8S 4L8, Canada. Electronic address: rajaba@mcmaster.ca.

PMID: 38640530
DOI: 10.1016/j.foodchem.2024.139320

Abstract

4(5)-methylimidazole (4-MeI) is a potential carcinogen widely used in food colours. EU regulations specify a maximum allowable concentration of 200 ppm for 4-MeI in caramel colours. This study reports an electrochemical determination technique for 4-MeI in caramel colours for the first time. The effect of pH and interference from air were studied to optimize the detection conditions on a glassy carbon electrode in aqueous alkaline solutions using square wave voltammetry (SWV) technique. The concentration of 4-MeI was quantitatively measured down to 10 μM (∼0.8 ppm). Traditional methods such as HPLC, GC, spectrometry and immunoassays involve either expensive instrumentation and reagents or time consuming preparation and detection processes. This study demonstrates the possibility of rapid and simple electrochemical determination of (4-MeI) in food colours with minimum workup using a portable potentiostat.

Keywords: 4-Methylimidazole (4-MeI); Carcinogen detection; Diffusion limited redox; Electrochemical sensing; Food colour and caramel colour safety; Rapid detection; pH dependent oxidation.