超高效液相色谱-四极杆/静电场轨道阱高分辨质谱测定蔬菜中的百草枯

Determination of Paraquat in Vegetables by Ultra Performance Liquid Chromatogra-phy-Quadrupole/Electrostatic Field Orbitrap High Resolution Mass Spectrometry

基于超高效液相色谱-四极杆/静电场轨道阱高分辨质谱技术(UHPLC-Q-Exactive MS),建立了蔬菜中百草枯的快速检测方法。蔬菜样品采用乙腈-0.2%甲酸水溶液(1∶1,体积比)提取2次,乙二胺-N-丙基硅烷化硅胶(PSA)和十八烷基硅烷键合硅胶(C18)分散固相萃取净化。目标物经Acquity UPLC BEH HILIC柱(100 mm×2.1 mm,1.7μm)分离,以乙腈-0.2%甲酸水溶液(含50 mmol/L甲酸铵)为流动相梯度洗脱,在电喷雾正离子(ESI+)模式下电离,高分辨质谱平行反应监测(PRM)扫描模式下采集数据进行定性定量分析。结果表明:不同蔬菜基质中百草枯在各自的质量浓度范围内线性关系良好,相关系数(r^2)为0.992 7~0.999 4,检出限为0.1~0.5μg/kg,定量下限为0.4~1.8μg/kg,平均回收率为70.8%~113%,相对标准偏差为0.30%~7.9%。该方法前处理简单、快速,可用于蔬菜中百草枯的快速筛查和定量分析。

A rapid screening and quantitative method was developed for the determination of paraquat in vegetables by ultra performance liquid chromatography-quadrupole/electrostatic field orbitrap high resolution mass spectrometry(UHPLC-Q-Exactive MS).The vegetable samples were extracted twice with acetonitrile-0.2%formic acid(1∶1,by volume),and cleaned up by dispersive solid phase extraction with N-propyl ethlene diamine(PSA)and C18.Separation of the target compounds was performed on an Acquity UPLC BEH HILIC(100 mm×2.1 mm,1.7μm)column with acetonitrile and 0.2%formic acid containing 50 mmol/L ammonium formate as mobile phases by gradient elution.The quantitative and qualitative analysis were carried out by high resolution mass spectrometry with electrospray ionization(ESI)source in positive ion acquisition mode under parallel reaction monitoring(PRM)mode.Results showed that there were good linear relationships for paraquat in different vegetables matrixes in corresponding concentration ranges with correlation coefficients(r 2)of 0.992 7-0.999 4.The limits of detection(LOD)and the limits of quantitation(LOQ)were in the ranges of 0.1-0.5μg/kg and 0.4-1.8μg/kg,respectively,while the recoveries ranged from 70.8%to 113%with relative standard deviations(RSD)of 0.30%-7.9%.The method is simple and rapid,and could be used for the quick screening and quantitative analysis of paraquat in vegetables.