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

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-ESI MS/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Waters Atlantis(d C18色谱柱分离,5 mmol/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0.990 0~0.999 9。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(S/N=10)为0.2~1.5μg/kg。

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

A liquid chromatography coupled with electrospray ionization tandem mass spectrometric (LC-ESI MS/MS) method was developed for the determination of eight benzoylphenylurea insecticide residues including,triflumuron,teflubenzuron,flufenoxuron,diflubenzuron,chlorfluazuron,hexaflumuron,chlorobenzuron 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~((R))d C_(18) column with 5 mmol/L aqueous ammonium acetate(A)-acetonitrile(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.