气相色谱-负化学源质谱联用法测定水产品及食用油中氟乐灵的残留量

建立了一种可用于水产品及食用油中氟乐灵残留量分析的分散型固相萃取-气相色谱-负化学离子源质谱方法。水产品及食用油经乙腈提取，4 ℃冷藏后，采用分散型固相萃取法净化，由气相色谱-负化学离子源质谱选择离子监测技术进行测定与确证，同位素内标法定量。在1~40 μg/L范围内氟乐灵农药的线性关系良好；方法定量限（LOQ）为0.02 μg/kg；对鳗鱼、烤鳗、梭子蟹、小龙虾、猪油和橄榄油等6种复杂基质进行1.0、2.0和3.0 μg/kg等3个水平的添加回收试验，平均回收率均处于80%~100%之间，RSD≤10.3%；无干扰现象出现。该方法可作为水产品及食用油中氟乐灵残留检测的确证方法。

Determination of trifluralin residue in aquatic products and edible oils by gas chromatography-negative chemical ionization mass spectrometry

A confirmatory method was established for the determination of trifluralin residue in aquatic products and edible oils with the technique of offline disperse solid phase extraction and gas chromatography-negative chemical ionization mass spectrometry (DSPE-GC-MS/NCI). Trifluralin was extracted from aquatic products and edible oils with acetonitrile, and liquid-liquid partitioning formed by adding anhydrous magnesium sulfate followed by a simple cleanup step known as dispersive solid-phase extraction. The aliquot was analyzed by GC-MS/NCI using isotope internal standard method. The method was reliable and stable. The recoveries of trifluralin were in the range from 80% to 100% at three spiked levels of 1.0, 2.0, and 3.0 μg/kg, and the RSDs were not more than 10.3%. The linearity of method was good from 1 to 40 μg/L, and the LOD was 0.02 μg/kg. This method can be used as a conclusive evidence method for the determination of trifluralin residue in aquatic products and edible oils.