Determination of Ethyl Carbamate in Fermented Foods by GC-HRMS

Abstract

A new sensitive method to quantify ethyl carbamate (EC) in fermented foodstuffs by gas chromatography-high resolution mass spectrometry (GC-HRMS) detection has been developed. EC was extracted from fermented foods by Extrelut extraction, followed by solid phase extraction (SPE) clean-up with Florisil column prior to GC-HRMS analysis. Deuterium-labelled EC was used as internal standard. Two analyte ions of the native and the labelled EC were monitored, one for quantification and one for confirmation of EC. The method was shown to be highly sensitive with low decision limit (CCα) and detection capability (CCβ) of less than 0.03 and 0.05 μg kg−1 respectively. Within-laboratory repeatability (% CV) were 6.2, 5.5 and 6.1% (fish sauce sample); and 3.2, 2.1, and 3.3% (shrimp paste sample) at spike levels of 0.2, 0.4 and 0.6 μg kg−1 respectively. Recoveries were 98, 99 and 98% (fish sauce sample); and 97, 101 and 100% (shrimp paste sample) at spike levels of 0.2, 0.4 and 0.6 μg kg−1 respectively. Method validation was performed according to the European Commission Decision 2002/657/EC and all criteria were fulfilled. This method is the first fully validated method with Extrelut extraction, Florisil clean-up, and high resolution mass spectrometry as detection means for the analysis of EC in fermented foods. The method had also been successfully applied to a variety of fermented foodstuffs.