溶剂提取/水蒸气蒸馏-分散液液微萃取-稳定同位素稀释-GC-MS/MS测定咸鱼中的挥发性亚硝胺

Determination of volatile nitrosamines in salted fish by stable isotope dilution-gas chromatography-tandem mass spectrometry with solvent extraction/steam distillation connecting with dispersion liquid-liquid microextraction

中文关键词:  挥发性亚硝胺  组合式经典样品前处理  咸鱼  气相色谱-串联质谱法

英文关键词:volatile N-nitrosamines  combing classic sample Pretreatments  salted fish  gas chromatography-tandem mass spectrometry  

中文摘要:

      目的 建立溶剂提取（SE）、水蒸气蒸馏（SD）分别与分散液液微萃取（DLLME）有效组合，进行样品前处理，稳定同位素稀释气相色谱-串联质谱法（GC-MS/MS）快筛和定量咸鱼中挥发性亚硝胺（VNA）的新方法。方法 样品加入9种VNA稳定同位素标记物，分别进行SE（甲醇-水为溶剂）和SD处理，提取液和蒸馏液分别进行DLLME，以GC-MS/MS多反应监测（MRM）模式进行检测。结果 方法在1-100 ng/mL范围内各VNA线性良好，R2为0.9920-0.9999；SE-DLLME处理简便快速，二甲基亚硝基胺（NDMA）检出限（LOD）为0.79 μg/kg、定量限（LOQ）为2.63 μg/kg，其他VNA的LOD为0.03 – 0.43 μg/kg、LOQ为0.10 – 1.44 μg/kg，可满足咸鱼中VNA合格性快筛的需要；SD -DLLME处理，NDMA的LOD为0.06 μg/kg、LOQ为0.21 μg/kg，其他VNA的LOD为0.01 – 0.40 μg/kg、LOQ为0.03– 1.30 μg/kg，可满足关注浓度以下VNA定量检测的需要；方法总体加标回收率分别为89.81%~105.10%，相对标准偏差（RSDs）为2.70%~7.30%。结论 该方法样品处理成本低廉，准确性好，为咸鱼VNA的合格性快筛和低含量水平试样的定量提供了有价值的参考方法。

英文摘要:

      Objective To establish a new screening and quantifying method for determination of volatile N-nitrosamines (VNA) in salted fishes with isotope dilution gas chromatography-tandem mass spectrometry(GC-MS/MS)and combing the classic solvent extraction(SE)and steam distillation (SD) to dispersing liquid-liquid microextraction (DLLME) respectively. Method The samples were fortified with stable isotope labelled analytes, and extracted homogeneously with SE using methanol-water solution as solvent and SD respectively, then with DLLME enrichment and purification for both the extracting solutions and the VNAs were analyzed by GC-MS/MS with multi-reaction monitoring (MRM) mode. Results Good linearity for each VNA was obtained within the range of 1-100 ng/mL, R2 were ranging from 0.9920 to 0.9999. With SE-DLLME, the limits of detection (LOD) and limit of quantification (LOQ) were 0.79 μg/kg and 2.63 μg/kg respectively for dimethylnitrosamine (NDMA); LODs were 0.03-0.43 μg/kg and LOQs were 0.10-1.44μg/kg for other VNAs; the qualification fast screening can be met with this combined sample pretreatment. With SD-DLLME,the LOD and LOQ were 0.06 μg/kg and 0.21 μg/kg respectively for NDMA; LODs were 0.01-0.40 μg/kg and LOQs were 0.03-1.30 μg/kg for other VNAs; quantification for the samples with VNAs concentrations below the concerning concentration with this combined sample pretreatment. Overall recoveries were 89.81%~105.10% with relative standard deviations (RSDs) ranging from 2.70% to 7.30%. Conclusion This method was low cost, accurate and provides a valuable reference for monitoring the VNA risk of salted fish.