色谱

色谱 ›› 2014, Vol. 32 ›› Issue (4): 433-437.DOI: 10.3724/SP.J.1123.2013.12030

• 庆祝《色谱》创刊三十周年暨卢佩章院士九十华诞专刊-研究论文 • 上一篇    下一篇

基于冷冻熔炼的液-液萃取/气相色谱法测定啤酒中的N-二甲基亚硝胺

彭俏容1,2, 唐涛1,2, 于淑新2, 孙元社2, 雷武1, 王风云1, 张维冰3, 李彤2   

  1. 1. 南京理工大学, 江苏 南京 210094;
    2. 大连依利特分析仪器有限公司, 辽宁 大连 116023;
    3. 华东理工大学, 上海 200237
  • 收稿日期:2013-12-25 修回日期:2014-02-24 出版日期:2014-04-08 发布日期:2014-03-28
  • 通讯作者: 李彤
  • 基金资助:

    国家重大科学仪器设备开发专项项目（2012YQ12004401，2012YQ12004403）；国家自然科学基金项目（51242001）.

Determination of N-nitrosodimethylamine in beer by frozen zone melting liquid-liquid extraction/gas chromatography

PENG Qiaorong1,2, TANG Tao1,2, YU Shuxin2, SUN Yuanshe2, LEI Wu1, WANG Fengyun1, ZHANG Weibing3, LI Tong2   

  1. 1. Nanjing University of Science and Technology, Nanjing 210094, China;
    2. Dalian Elite Analytical Instruments Co., Ltd., Dalian 116023, China;
    3. East China University of Science and Technology, Shanghai 200237, China
  • Received:2013-12-25 Revised:2014-02-24 Online:2014-04-08 Published:2014-03-28

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摘要：

建立了一种新型的冷冻熔炼液-液萃取法直接提取啤酒中的N-二甲基亚硝胺（N-nitrosodimethylamine，NDMA），萃取液经GC-FID分析，双柱法定性，外标法定量。优化的前处理条件为：以二氯甲烷为萃取溶剂，啤酒样品和萃取溶剂的体积比为9：1，-19 ℃下冷冻16 h。结果表明：NDMA在5~200 mg/L范围内具有良好的线性关系（r2=0.9996）；在5、10和20 mg/L 3个加标水平下的回收率分别为84.94%、83.24%、85.14%，平行7次测定的相对标准偏差（RSD）分别为3.06%、3.19%、2.63%。与常规液-液萃取方法（需要经过蒸馏、萃取、旋蒸、氮吹4个步骤）相比，本方法稳定、可靠，且操作简单，有机溶剂消耗量少。

关键词: N-二甲基亚硝胺, 冷冻熔炼液-液萃取, 啤酒, 气相色谱法

Abstract:

A simple and effective sample enrichment method of frozen zone melting liquid-liquid extraction was optimized and validated for the analysis of trace N-nitrosodimethylamine (NDMA) in beer samples. The method was based on high pressure liquid-liquid extraction with a low temperature frozen step. The 90 mL beer was placed in a container with 10 mL dichloromethane. After agitation, the sample was kept in a freezer for 16 h at -19 ℃. The organic extract was analyzed by gas chromatography with a flame ionization detector (GC-FID). The accuracy, precision, detection and quantification limits and linearity of the method were evaluated. The results showed that the calibration curve of NDMA was linear in the range of 5-200 mg/L with a good correlation coefficient (r2) of 0.9996. The recoveries at the spiked levels of 5, 10 and 20 mg/L were 84.94%, 83.24%, 85.14% with the relative standard deviations (n=7)of 3.06%, 3.19%, 2.63%, respectively. The ordinary extraction method of N-nitrosodimethylamine in beer includes the four steps of low-temperature distillation, liquid-liquid extraction, rotary evaporation and nitrogen blowing concentration. With the extremely low volume of solvent used, the proposed extraction method proved to be easy and simple, and adequate for high-throughput analysis at low cost.

Key words: N-nitrosodimethylamine, beer, frozen zone melting liquid-liquid extraction, gas chromatography (GC)

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