QuEChERS结合高效液相色谱-串联质谱法测定酱油中的4-甲基咪唑

建立了QuEChERS技术结合高效液相色谱-串联质谱对酱油中的4-甲基咪唑进行测定的HPLC-MS/MS法。样品以水和乙腈提取后,盐析离心分层,上清液用固相吸附剂(Primary Secondary Amine,PSA)进行净化。在优化的色谱及质谱条件下,采用ESI正离子模式电离,多反应监测(Multi-selected reaction monitoring,MRM)模式扫描测定。4-甲基咪唑在5.0~200μg/L范围内线性良好,相关系数r为0.999 4,3个浓度添加水平的平均回收率范围在90.7%~103.6%之间,相对标准偏差为2.76%~5.72%。方法检出限(LOD)和定量限(LOQ)分别为3.0μg/kg和10μg/kg。该方法操作简便快速,方法学结果表明方法回收率高、灵敏度高、精密度好,可用于实际测定酱油中的4-甲基咪唑。

Determination of 4-Methylimidazole in Soysauce by QuEChERS Coupled With High Performance Liquid Chromatography-Tandem Mass Spectrometry

A method for determination of 4-methylimidazole (4-MI) in soysauce was created by QuEChERS coupled with high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). Samples were extracted by water and acetonitrile, then salted out and centrifuged. Supernatant was purified with primary secondary amine (PSA) and finally detected under the optimized chromatographic and mass spectrometer conditions, data were obtained with electrospray (ESI +) mode ionization and multi-selected reaction monitoring (MRM) scanning detection. The calibration curves of 4-methylimidazole exhibited good linearity within the concentrations of 5.0~200 μg/L with the correlation coefficient(r=0.999 4). The average recoveries of three concentration levels ranged from 90.7 % to 103.6 %, while the relative standard deviations (RSDs) were 2.76 %~5.72 %. The limits of detection (LOD) and limits of quantitation (LOQ) were 3.0 μg/kg and 10 μg/kg, respectively. The methodological results indicated that it had high recovery, good sensitivity, high precision and was suitable for practical determination of 4-methylimidazole in soysauce.