在线净化液相色谱-高分辨质谱法快速筛查果蔬中212种农药残留

摘要

A new method and mass spectral database for screening pesticide residues in fruits and vegetables by liquid chromatography-high resolution benchtop/orbitrap mass spectrometry (HRMS) with on-line cleanup were developed.The samples were extracted with acetonitrile containing 0.1％ acetic acid,then purified and collected with a Cyclone-P column.The analytes were separated on a C18 column with acetonitrile-0.5 mmol/L ammonium acetate containing 0.1％ acetic acid as mobile phase by gradient elution.212 pesticides residues were analyzed by high-resolution mass spectrometry Q-Orbitrap in full scan/ddMS2 mode under switching positive and negative mode.The calibration curves were linear in the range of 0.5-50 μg/L with correlation coefficients more than 0.998.The limits of quantitation(LOQs) reached to 5 μg/kg.The average recoveries of the analytes at a spiked level of 10 μg/kg were in the range of 58.3％-129.4％,with their relative standard deviations of 2.8％-16.0％.The method could be used for the rapid screening of 212 compounds in fruits and vegetables by means of accurate mass of quasi-molecular ion,retention time,isotope ratio and qualitative fragments without any reference standards.%基于在线净化液相色谱-四极杆/静电场轨道阱高分辨质谱技术建立了快速筛查果蔬中212种农药残留的方法和数据库.样品经0.1％乙酸乙腈提取,提取液经在线净化柱(Cyclone-P)净化、富集后,以乙腈-0.5 mmol/L乙酸铵(含0.1％乙酸)为流动相梯度洗脱,待测物经C18分析柱色谱分离后,采用四极杆/静电场轨道阱高分辨质谱以正负同时扫描的Full Scan/ddMS2模式进行检测.结果表明,212种农药在0.5 ～50μg/L范围内呈良好线性,相关系数均大于0.998.方法的定量下限(LOQ)均可达到5μg/kg.通过实际样品的加标回收试验,212种农药在10μg/kg的加标回收率为58.3％ ～129.4％,相对标准偏差(RSD)为2.8％～16.0％.该方法利用精确质量数、保留时间、同位素峰比、二级碎片等多个定性信息可在无标准物质的情况下实现对果蔬中212种化合物的快速筛查与确证.