The application of QuEChERS coupled to liquid chromatography/quadrupole time-of-flight mass spectrometry (LC-Q-TOF/MS) for screening 281 pesticide residues in apples, toma-tos, and cabbages has been investigated. The established method includes the extraction by acetonitrile/acetic acid (99: 1, v/v) , and clean-up by primary secondary amine (PSA) sor-bent. The resultant residues were further analyzed by LC-Q-TOF/MS. For apples, tomatos, and cabbages, the percentages of pesticides with the average recoveries (n = 5) in the range of 70% - 120% were 98. 6%, 99. 3%, and 98. 2% , respectively; and the relative standard deviations (RSDs) for the recoveries were not more than 20%; in the concentration range of 0. 25 - 10 MRL, the percentages of the pesticides with the correlation coefficients (r2) greater than 0. 99 were 95. 7%, 96. 1%, and 98. 2%, respectively; the LODs were 0.03 -4.47 μg/kg, 0.01 -4.49 μg/kg and 0. 02 -3. 61 μg/kg, respectively. Rapid screening and confirmation can be achieved with accurate mass database and library search without the standard compounds. The method has been applied to 30 fruit and vegetable samples randomly purchased from the local markets, and the 13 pesticides were detected. It was found that the level of methamidophos in one cabbage sample exceeded the MRL regulated by China of GB 2763-2012 and the MRL regulated by European Union (EU) , and the level of rotenone in one tomato sample exceeded the MRL regulated by EU.%建立了苹果、番茄和甘蓝中281种农药残留的QuEChERS结合液相色谱-四极杆/飞行时间质谱(LC-Q-TOF/MS)快速筛查方法.方法采用1％醋酸乙腈提取样品,经丙基乙二胺(PSA)净化,LC-Q-TOF/MS测定.281种农药在苹果、番茄和甘蓝中3个添加水平下的回收率在70％ ～ 120％范围的比例分别为98.6％、99.3％和98.2％；回收率的相对标准偏差(RSD)均≤20％(n=5)；在0.25 ～ 10倍最大残留限量(MRL)的含量范围内,线性相关系数r2≥0.99的农药比例分别为95.7％、96.1％和98.2％；检出限分别为0.03 ～ 4.47、0.0l ～4.49和0.02 ～ 3.61 μg/kg.本方法采用精确质量数据库和谱图库检索的方式,实现了不用农药标准品对照而完成对果蔬中农药残留的快速筛查,提高了定性鉴别的准确性.应用所建立的方法对30个市售果蔬样品进行筛查,共检出13种农药残留.其中,甘蓝中甲胺磷的含量超过了GB 2763-2012 《食品安全国家标准·食品中农药最大残留限量》和欧盟的MRL；番茄中鱼藤酮的含量超出欧盟的MRL.
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