Development and validation of analytical methods for ethyl carbamate in various fermented foods

The aim of this work was to develop and validate analytical methods for ethyl carbamate (EC) in various food matrices. Column chromatography was used for the analysis of EC in kimchi, a fermented soybean paste (doenjang), a fermented fish product (jeotgal), yoghurt, bread, and cheese. To remove the fat in the bread and cheese, a Florisil cartridge was selected. The volume of dichloromethane in the chromatography column was optimised to 60 mL for the kimchi, cheese, and fermented soybean paste. For the bread, jeotgal, and yoghurt, the best recovery rate was found by using 100 mL of dichloromethane. For the accurate analysis of EC in the vinegar, 150 mL of dichloromethane and a neutralisation process (pH = 8.0) were required. In the standard curve of EC, satisfactory linearity (R2 = 0.998) was shown. The limit of quantification (LOQ) was 10 ng/mL and the recovery rates ranged from 76.9% to 118.1%. Intra- and inter-assay precision ranged from 3.5% to 34.2% and 3.8% to 41.9%, respectively.