同位素稀释-气相色谱串联质谱法测定啤酒中4种亚硝胺类化合物

目的 建立啤酒中4种N-亚硝胺类化合物（N-亚硝基二甲胺、N-亚硝基二乙胺、N-亚硝基二丙胺、N-亚硝基二苯胺）的同位素稀释固相萃取-气相色谱串联质谱测定方法。 方法 样品经活性炭固相萃取小柱富集、二氯甲烷洗脱，洗脱液经氮吹浓缩定容后，采用INNOWAX毛细管色谱柱分离，多反应监测（MRM）模式检测，同位素稀释内标法定量。 结果 各物质在5 μg/L~200 μg/L范围内线性关系良好，相关系数均大于0.9995。方法的检出限为0.03-0.10 μg/L，定量限为0.10~0.33 μg/L。不同水平的加标回收率为72.1%~100.3%，相对标准偏差为1.5%~9.5%（n=6）。 结论 该方法操作简单，灵敏度和准确度高，适用于啤酒中4种N-亚硝胺类化合物的测定。

Determination of four N-nitrosamines in beer by isotope dilutiongas chromatography-tandem mass spectrometry

Abstract: Objective To establish an analytical method for determination of four N － nitrosamines ( N － nitrosodimethylamine， N － nitrosodiethylamine， N － nitrosodi － n － propylamine， N － nitroso diphenylamine) in beer samples by isotope dilution solid－ phase extraction and gas chromatography － tandem mass spectrometry( SPE － GC － MS /MS) . Methods N － nitrosamines in the samples were concentrated with activated carbon SPE column and eluted with dichloromethane. The eluent was concentrated to 1. 0 ml under nitrogen flow. The compounds were separated by INNOWAX capillary chromatographic column and detected in multiple reaction monitoring ( MRM) mode. Finally， the isotope dilution internal standard method was used for quantitative analysis. Results The substances had a good linear relationship in the range of 5 μg /L to 200 μg /L， with the correlation coefficients all greater than 0. 9995. The limits of detection ( LODs) were 0. 03 μg /L to 0. 10 μg /L and the limits of quantification ( LOQs) were 0. 10 μg /L to 0. 33 μg /L. The average recovery rates of different levels were 72. 1% － 100. 3% ，with the relative standard deviations ( RSDs) in the range of 1. 5% － 9. 5% . Conclusion The method is simple， sensitiveand accurate. And it is suitable for the detection of four N － nitrosamines in beer.