分散固相萃取-超高效液相色谱-串联质谱法测定酱油中的2-甲基咪唑和4-甲基咪唑  

Quantitative determination of 2-and 4-methylimidazole in soy sauce using dispersive solid phase extraction and ultra-high performance liquid chromatography-tandem mass spectrometry

作　　者：吴玉銮 冼燕萍 郭新东 罗海英 王莉 韩婉清 陈立伟 李核[2] 

机构地区：[1]广州质量监督检测研究院,广州510110 [2]华南师范大学化学与环境学院,广州510006

出　　处：《食品安全质量检测学报》2014年第5期1357-1364,共8页Journal of Food Safety and Quality

基　　金：国际科技合作专项(2013DFH30070);广东省科技厅项目(2010B10800027)~~

摘　　要：目的建立测定酱油中2-甲基咪唑和4-甲基咪唑的分散固相萃取-超高效液相色谱-串联质谱(dSPE-UPLC-MS/MS)分析方法。方法样品加入同位素内标后,以水稀释,并调至碱性,用乙腈提取,加入无水MgSO4和无水 NaAC,老抽样品再经 N-丙基乙二胺(PSA)/多壁碳纳米管(MWNTs)分散净化,采用 UPLC BEH HILIC (50 mm×2.1 mm,1.7μm )色谱柱分离,以乙腈-10 mmol/L乙酸铵溶液(含0.1%甲酸, v/v)为流动相等度洗脱,采用电喷雾离子源串联质谱,正离子多反应监测模式检测,以同位素内标定量。结果2-甲基咪唑和4-甲基咪唑的方法检出限均为1.5μg/kg；在1.0~100μg/L浓度范围内线性关系良好,相关系数均大于0.999；在生抽和老抽样品中进行3个水平的添加实验,平均回收率(n=6)为89.6%~117.2%,日内精密度为4.8%~12.9%,日间精密度(n=5)小于15%。结论本方法简单快速、准确灵敏,适用于酱油中2-甲基咪唑和4-甲基咪唑的测定。Objective To establish a simple and rapid method for determination of 2-methylimidazole (2-MID) and 4-methylimidazole (4-MID) in soy sauce using dispersive solid phase extraction (dSPE) clean-up and ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Methods The isotope internal standard was added into the samples, which then was diluted with water and adjusted to alkaline, processed by liquid-liquid extraction with acetonitrile, followed by adding anhydrous MgSO4 and anhydrous NaAC. Then the extract of dark soy sauce was purified by primary secondary amine (PSA) sorbent plus multi-walled carbon nanotubes (MWNTs). The ultimate solution was separation with UPLC BEH HILIC (50 mm×2.1 mm, 1.7 μm), elution with acetonitrile and 10 mmol/L ammonium acetate (containing 0.1% formic acid, v/v), and detection with tandem mass spectrometry under ESI at positive and multiple reaction monitoring (MRM) mode. The targets were quantified by isotope internal standard. Results The limit of detection (LOD) of the MIDs were both 1.5 μg/kg, and the linear range were 1.0~100 μg/L with the correlation coefficients larger than 0.999. The average recoveries ranged from 89.6% to 117.2%, and within-day precisions were in a range of 4.8%~12.9% when three levels of standard were spiked into light and dark soy sauce. The inter-day precisions were less than 15%. Conclusion The developed method is simple, rapid, accurate and sensitive for the detection of 2-MID and 4-MID in soy souse.

关 键 词：2-甲基咪唑 4-甲基咪唑 超高效液相色谱-串联质谱法 分散固相萃取 酱油 

分 类 号：O657.63[理学—分析化学] TS264.21[理学—化学]