同位素稀释-气相色谱-质谱法测定发酵乳中氨基甲酸乙酯

建立了同位素稀释-气相色谱-质谱联用测定酸奶、奶酪等发酵乳中氨基甲酸乙酯（EC）含量的方法，通过优化前处理方法，考察了提取溶剂的种类、提取次数对样品提取效果的影响。在优化的实验条件下，使用氨基甲酸乙酯-d₅作为内标定量。结果表明：在0.05~20.0 mg/L范围内线性关系良好，线性相关系数为0.9998，检出限为0.02 mg/L；在3个加标水平下，样品的回收率在98.9%~102.9%之间，相对标准偏差为0.6%~4.8%。该方法前处理简单、提取效果好，具有比外标定量法更好的灵敏度和可靠性，适用于发酵乳中氨基甲酸乙酯含量的监控。

Determination of Ethyl Carbamate in Fermented Dairy Products by Isotope Dilution-GC/MS

A method for determination of ethyl carbamate in fermented dairy products was proposed by gas chromatography-mass spectrometry (GC/MS) with deuterium ethyl carbamate as isotopic internal standard. The types and times of extraction solvents were discussed to establish efficient pretreatment method. The results show that the calibration curve has good linearity in the range of 0.05-20 mg/L with the correlation coefficient of 0.999 8, and the limit of detection is 0.02 mg/L. The recoveries range from 98.9% to 102.9% with RSDs of 0.6%-4.8% in three levels. The method is simple, rapid, accurate, and can be applied in the quantification of ethyl carbamate in fermented dairy products.