title: Simultaneous determination of ethyl carbamate and 4-(5-)methylimidazole in yellow rice wine and soy sauce by gas chromatography with mass spectrometry.
abstract: We developed a new method, based on alkaline diatomite solid-phase extraction followed by gas chromatography with mass spectrometry, for the simultaneous determination of the toxic contaminants ethyl carbamate (EC) and 4-(5-)methylimidazole (4-MEI) in yellow rice wine and soy sauce. The optimal extraction conditions were defined. With the application of alkaline diatomite solid-phase extraction, damage to the capillary column by organic acids was greatly reduced. With deuterated EC used as the internal standard, the linearity of the calibration curves for EC and 4-MEI was good with correlation coefficient above 0.99. In a spiked experiment with EC and 4-MEI in yellow rice wine and soy sauce, recovery of the added EC was 80.5-102.5% and that of 4-MEI was 78.3-92.8%. The limit of quantification and limit of detection for EC were 6.0 and 2.0 μg/kg, respectively, and for 4-MEI were 15.0 and 5.0 μg/kg, respectively. The validation results demonstrate that the method is fast, simple, and selective, and therefore is suitable for simultaneously determining the presence of EC and 4-MEI in fermented food.
authors.affiliation: Center for Disease Control and Prevention of Zhejiang Province, Hangzhou, P. R. China.
authors.forename: Pinggu
authors.initials: P
authors.lastname: Wu
authors.forename: Liqun
authors.initials: L
authors.lastname: Zhang
authors.forename: Liyuan
authors.initials: L
authors.lastname: Wang
authors.forename: Jing
authors.initials: J
authors.lastname: Zhang
authors.forename: Ying
authors.initials: Y
authors.lastname: Tan
authors.forename: Jun
authors.initials: J
authors.lastname: Tang
authors.forename: Bingjie
authors.initials: B
authors.lastname: Ma
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Pan
authors.forename: Wei
authors.initials: W
authors.lastname: Jiang
mesh_terms: D002138:Calibration; D002852:Chromatography, Ion Exchange; D005504:Food Analysis / Q000379:methods; D005506:Food Contamination / Q000032:analysis*; D008401:Gas Chromatography-Mass Spectrometry; D007093:Imidazoles / Q000032:analysis / Q000737:chemistry*; D057230:Limit of Detection; D012275:Oryza; D015203:Reproducibility of Results; D052616:Solid Phase Extraction; D045730:Soy Foods / Q000032:analysis*; D014520:Urethane / Q000032:analysis / Q000737:chemistry*; D014920:Wine / Q000032:analysis*
chemical_list: D007093:Imidazoles; D014520:Urethane; C029899:imidazole
keywords: Ethyl carbamate; Gas chromatography with mass spectrometry; Methylimidazole; Soy sauce; Yellow rice wine