盐辅助分散液液微萃取结合气相色谱-串联质谱法快速检测啤酒中N-二甲基亚硝胺

Rapid determination of N-dimethyl nitrosamine in beer by salt-assisted dispersible liquid-liquid microextraction combined with gas chromatography-tandem mass spectrometry

中文关键词:  盐辅助分散液液微萃取  气相色谱-串联质谱法  N-二甲基亚硝胺  啤酒

英文关键词:salt assisted dispersing liquid-liquid microextraction  gas chromatography-tandem mass spectrometry  N-dimethylnitrosamine  beer

中文摘要:

      目的 建立盐辅助分散液液微萃取(salt assisted dispersi ble liquid-liquid microextraction, SADLLME)气相色谱-串联质谱法(gas chromatography-tandem mass spectrometry, GC-MS/MS)检测啤酒中N-二甲基亚硝胺(N-dimethylnitrosamine, NDMA)的分析方法。方法 取30 mL啤酒于50 mL的离心管中, 加入浓度为1 μg/mL的NDMA-d6甲醇溶液50 μL, 硫酸钠3 g, 振荡溶解, 快速打入二氯甲烷600 μL, 振荡1 min, 离心, 弃去上清液, 取下层有机相, 上机检测。结果 方法在考察浓度为1~100 μg/L的范围内线性良好, 相关系数大于0.998; 添加回收率为97.7%～104.8%, 相对标准偏差为4.07%～8.46%; 检出限为0.03 μg/L, 定量限为0.10 μg/L。实际样品检测显示, 啤酒样品中均检出含有NDMA, 但含量远低于国际限量5 μg/L, 处于较安全水平。结论 该方法具有样品处理简便、快速、成本低廉, 方法检出限极低, 准确度高, 可满足啤酒中NDMA检测的需要。

英文摘要:

      Objective To establish a method for determination of N-dimethylnitrosamine (NDMA) in beer by salt assisted dispersing liquid-liquid microextraction (SADLLME) combined with gas chromatography-tandem mass spectrometry (GC-MS/MS). Methods A 30 mL beer was put into a 50 mL centrifuge tube and 50 μL NDMA-d6 methanol solution with concentration of 1 μg/mL and 3 g sodium sulfate was added. After dissolution with manual vibrating, 600 μL dichloromethane was quickly injected to forming cloudy solution; then after shaking (1 min) and centrifugation, the bottom organic phase of sample solution was used for the determination by GC-MS/MS. Results This method was good linear in the concentration range of 1–100 μg/L, and the correlation coefficient was greater than 0.998. The recoveries were 97.7%–104.8% and the relative standards deviations were 4.07%–8.46%. The limit of detection (LOD) was 0.03 μg/L and the limit of quantitation was 0.10 μg/L. The actual sample tests showed that NDMA was detected in all beer samples but the content was far below the international limited of 5 μg/L, which was within the safe level. Conclusion This method is simple and fast, low cost, low detection limit and high accuracy, which can meet the need of detection of NDMA in beer.