顶空气相色谱-串联质谱法测定水产品中三甲胺的含量  

Determination of Trimethylamine in Aquatic Products by Headspace-Gas Chromatography-Tandem Mass Spectrometry

作　　者：郑耀林 卢贵婷 林秋凤[1] 莫淑梅 杨乐[1] 张树权 ZHENG Yaolin;LU Guiting;LIN Qiufeng;MO Shumei;YANG Le;ZHANG Shuquan(Dongguan Institute for Food and Drug Control,Dongguan 523808,China;College of Food Science and Technology,Guangdong Ocean University,Zhanjiang 524088,China)

机构地区：[1]东莞市食品药品检验所,东莞523808 [2]广东海洋大学食品科技学院,湛江524088

出　　处：《理化检验（化学分册）》2024年第12期1257-1262,共6页Physical Testing and Chemical Analysis(Part B:Chemical Analysis)

基　　金：广东省市场监督管理局科研攻关项目(2023SC11);东莞市社会发展科技面上项目(20221800902042)。

摘　　要：取10 g水产品样品,加入20 mL 5%(体积分数,下同)三氯乙酸溶液,均质1 min,离心5 min。上清液经脱脂棉过滤,收集滤液。残留物分别用15,10 mL 5%三氯乙酸溶液各提取一次,合并所有滤液,用5%三氯乙酸溶液稀释至50 mL。分取2.0 mL于20 mL顶空瓶中,压盖密封后用注射器从盖垫边缘注入5 mL 10%(质量分数)氢氧化钠溶液,在45℃下平衡40 min,所得气体进入气相色谱-串联质谱仪,在HP-INNOWAX毛细管色谱柱上以程序升温条件分离三甲胺,电子轰击离子源电离,多反应监测模式扫描,以所得特征离子对质荷比(m/z)58/42进行外标法定量,m/z 59/43和m/z 58/30进行定性。结果表明,三甲胺的质量浓度在0.2~50 mg·L^(-1)内和对应的定量离子对峰面积呈线性关系,检出限(3S/N)为0.3 mg·kg^(-1)。5,25,100 mg·kg^(-1)添加水平下的回收率为88.3%~94.0%,测定值的相对标准偏差(n=6)为1.1%~3.7%。方法用于鱼肉样品的分析,未检出三甲胺。将上述样品于-18,4℃保存7 d后,三甲胺的检出量分别为0.4,195 mg·kg^(-1),可能与放置过程中鱼肉被微生物降解成三甲胺有关。The 10 g of aquatic product sample was taken,and 20 mL of 5%(volume fraction,the same below)trichloroacetic acid solution was added.The mixture was homogenized for 1 min,and centrifuged for 5 min.The supernatant was passed through the defatted cotton,and the filtrate was collected.The residue was extracted with 15,10 mL of 5%trichloroacetic acid solution,respectively.All the filtrate was combined,and diluted to 50 mL with 5%trichloroacetic acid solution.An aliquot(2.0 mL)was placed into a 20 mL-headspace vial,which was sealed with a cap.Then 5 mL of 10%(mass fraction)sodium hydroxide solution was injected from the edge of the cap with a syringe.After equilibrating at 45℃for 40 min,the resulting gas was introduced into a gas chromatograph-tandem mass spectrometer.Trimethylamine was separated on HP-INNOWAX capillary column under programmed temperature conditions,ionized with an electron bombardment ion source,and scanned in multiple reaction monitoring mode.The characteristic ion pairs at mass to charge ratio(m/z)of 58/42 was used for quantitative analysis by the external standard method,and m/z 59/43 and m/z 58/30 were used for qualitative analysis.It was shown that linear relationship between the peak area of quantitative ion pair and mass concentration of trimethylamine was kept in the range of 0.2-50 mg·L^(-1),with detection limit(3S/N)of 0.3 mg·kg^(-1).-1 The recovery at the addition level of 5,25,100 mg·kg was found in the range of 88.3%-94.0%,with RSDs(n=6)of the determined values in the range of 1.1%-3.7%.The proposed method was used for the analysis of fish meat samples,and trimethylamine was not detected.The above sample was stored at-18,4℃for 7 d,giving the detection amounts of trimethylamine of 0.4,195 mg·kg^(-1),which might be related to the microbial decomposition of fish meat into trimethylamine during storage.

关 键 词：三甲胺 顶空气相色谱-串联质谱法 水产品 

分 类 号：O657.63[理学—分析化学]