DETERMINATION OF ETHYL CARBAMATE IN ALCOHOLIC BEVERAGES AND SOY-SAUCEBY GAS-CHROMATOGRAPHY WITH MASS-SELECTIVE DETECTION - COLLABORATIVE STUDY

A method using gas chromatography with mass selective detection for th e determination of ethyl carbamate (EC; also known as urethane) in alc oholic beverages and soy sauce was collaboratively studied by 17 labor atories including authors' laboratories. The method uses prepacked col umns for extraction of liquids with methylene chloride, and n-propyl c arbamate as the internal standard. A practice sample and 6 samples of distilled spirits, fortified wines, table wines, and soy sauces were a nalyzed by each collaborator. Each matrix included blind duplicates of incurred and fortified EC at 3 levels. Distilled spirits contained 50 -330 ng EC/g (ppb), fortified wine 40-160 ppb, table wine 10-50 ppb, a nd soy sauce 15-70 ppb. The ranges of the repeatability relative stand ard deviations, excluding outliers, were 4.03-6.63% for distilled spir its, 4.01-5.05% for fortified wine, 3.94-6.73% for table wine, acid 4. 70-8.49% for soy sauce. The ranges of the reproducibility relative sta ndard deviations, excluding outliers, were 8.53-9.49% for distilled sp irits, 6.84-12.02% for fortified wine, 8.86-18.47% for table wine, and 13.87-27.37% for soy sauce. Recoveries of added EC ranged from 87 to 93%. Recoveries relative to reference values, labeled as the internal standard, obtained by using gas chromatography/tandem mass spectrometr y with a triple quadrupole mass spectrometer ranged from 89 to 100%.