稳定同位素稀释-液相色谱-串联质谱法直接测定酒类中氨基甲酸乙酯

建立稳定同位素稀释-液相色谱-串联质谱直接测定酒类中氨基甲酸乙酯（ethyl carbamate，EC）新方法。酒样加入EC-d5内标，微孔滤膜后直接进样，经Waters XSELECT HSS T3 （2.1 mm×150 mm，3.5 μm）色谱柱，80%的水（含0.1%乙酸）和20%的乙腈为流动相，0.2 mL/min等度洗脱分离，电喷雾正离子（ESI＋）多重反应监测模式质谱检测（EC-d5：m/z 94.9/63、94.9/44；EC：m/z 89.9/62、89.9/44）。结果表明，EC的检出限和定量限分别不大于2 ng/mL和5 ng/mL，验证质量浓度（5～500 ng/mL）范围内保持线性，r2 = 0.999 8。回收率为92.4%～108.5%，相对标准偏差为3.12%～8.65%（n=6）。实际应用显示，与冷藏（4 ℃）相比，葡萄酒置于室温（21～28 ℃）长期贮藏可导致EC显著升高；烫酒（95 ℃）可导致蒸馏酒和配制酒EC显著升高。

Direct Determination of Ethyl Carbamate in Alcoholic Drinks by Stable Isotope Dilution Liquid Chromatography-Tandem Mass Spectrometry

A new method was established for direct determination of ethyl carbamate (EC) in alcoholic beverages by stable
isotope dilution liquid chromatography-tandem mass spectrometry. After being spiked with EC-d5 and filtered with micropore
filters, the samples were directly injected. The chromatographic separation was carried out on a Waters XSELECT
HSS T3 column (2.1 mm × 150 mm, 3.5 μm) with a mobile phase of 80% water containing 0.1% (V/V) acetic acid and 20%
acetonitrile in an isocratic elution mode at a flow rate of 0.2 mL/min. The mass spectrometry detection was performed by
positive electrospray ionization (ESI+) and monitored in a multiple reaction monitoring (MRM) mode (m/z 94.9/63 and
94.9/44 for EC-d5; m/z 89.9/62 and 89.9/44 for EC). The limit of detection (LOD) was lower than 2 ng/mL and the limit of
quantification (LOQ) was lower than 5 ng/mL. The calibration curve showed good linearity in the range of 5–500 ng/mL
with a correlation coefficient of 0.999 8. The spiked recoveries of EC ranged from 92.4% to 108.5%, and the relative
standard deviations (RSDs) were 3.12%–8.65% (n = 6). EC content increased significantly when wine was stored at room
temperatures (21–28 ℃) than at 4 ℃ as determined by the proposed method. Heating (at 95 ℃) before drinking resulted in
significantly increased levels of EC content in distilled spirits and mixed alcoholic drinks.