DETERMINATION OF ETHYL CARBAMATE IN SOY SAUCES

The potential carcinogen ethyl carbamate was determined in 18 soy sauces, which were classified in three groups: fermented, non-fermented and those with unclear production process. The sample preparation included a solid-phase extraction with Extrelut. Non-polar compounds were separated by rinsing the column with n-pentane before dichloromethane elution. The concentrated extracts were measured by gas chromatography-selected ion monitoring-mass spectrometry (GC-SIM-MS) using chemical ionization with methane as reagent gas. Ethyl carbamate as well as propyl carbamate as internal standard were detected by two representative mass fragments down to a detection limit of 1 ppb. The fermented sauces showed a tendency to higher ethyl carbamate concentrations than the non-fermented sauces.