果蔬中8种苯甲酰脲类农药残留量的液相色谱-串联质谱法测定

Determination of Eight Benzoylphenylurea Insecticides Residues in Fruits and Vegetables Using Liquid Chromatography-Tandem Mass Spectrometry

建立了果汁蔬菜中8种苯甲酰脲类（杀虫脲、氟苯脲、氟虫脲、氟啶脲、除虫脲、氟铃脲、灭幼脲、氟丙氧脲）农药残留量的液相色谱-电喷雾串联质谱（LC—ESIMS／MS）测定方法。样品用乙腈提取后无需净化，经盐析过滤并以水稀释（1：1）后，经WatersAtlantisdC18色谱柱分离，5mmol／L乙酸铵水溶液和乙腈梯度洗脱，以电喷雾电离串联质谱在负离子多反应监测（MRM）模式下进行测定并确证，外标法定量。8种苯甲酰脲类农药在1．0—100μg／L范围内线性良好，相关系数为0．9900—0．9999。对8种农药在毛豆基质中3个添加水平下的回收率进行测定，平均回收率为92％～110％，相对标准偏差为5．5％～12％。方法的检出限（S／N=3）为0．04～0．42μg／kg，定量下限（影N=10）为0．2～1．5μg/kg。

A liquid chromatography coupled with electrospray ionization tandem mass spectrometric （ LC - ESI MS/MS） method was developed for the determination of eight henzoylphenylurea insecticide residues including, triflumuron, teflubenzuron, flufenoxuron, diflubenzuron, chlorfluazuron, hexaflumuron, ehlorobenzuron and lufenuron in fruits and vegetables. The insecticide residues were extracted from the samples by acetonitrile. The extracts were separated from water by addition of salts and diluted with water（1 ： 1 ） without any further clean-up step. The separation of eight insecticides was performed on a Waters Atlantis d C18 column with 5 mmol/L aqueous ammonium acetate（A） - aeetonitrile（B） as the mobile phase for gradient elution. The identification of target compounds was carried out by MS with negative ESI under multiple reaction monitoring （MRM） mode. Pesticides were quantified by external method using matrix-matched calibration standards. The method showed good linearity over the range of 1.0 - 100 μg/L for eight benzoylphenylurea insecticides with correlation coefficients of 0. 990 0 -0. 999 9. The mean recoveries from green soybean samples at three fortification levels of 10, 20, 50 μg/kg ranged from 92% to 110% with relative standard deviations （RSDs） of 5.5% -12%. The limits of detection （S/N = 3 ） were 0. 04 -0. 42 μg/kg and the limits of quantitation（ S/N = 10） were 0. 2 - 1.5 μg/kg.