加压流体萃取-气相色谱质谱法测定土壤和沉积物中27种拟除虫菊酯类农药

建立了加压流体萃取-气相色谱质谱法测定土壤和沉积物中27种拟除虫菊酯类农药的方法。以丙酮/正己烷(V∶V=1∶1)为萃取溶剂,在120℃和10. 3 MPa条件下静态萃取7 min,循环3次,石墨化炭黑串接氨丙基键合硅胶固相萃取柱净化,HP-5MS UI色谱柱分离,优化了提取和分析过程的重要条件。方法检出限为0. 001~0. 012 mg/kg,土壤中低、高浓度的加标回收率范围分别为68. 3%~123%和75. 3%~115%,沉积物中低、高浓度的加标回收率范围分别为67. 1%~120%和78. 6%~110%,单一目标物的相对标准偏差(RSD)均<20%(n=6)。实验结果表明,该方法消耗溶剂少、效率高、检出限低、精密度和准确度好,适用于土壤和沉积物中拟除虫菊酯类农药残留的测定。

Determination of 27 Pyrethroid Pesticide Residues in Soils and sediments by Gas Chromatography Mass Spectrometry with Pressurized Fluid Extraction

We developed a strategy based on gas chromatography-mass spectrometry combined with pressurized fluid extraction,to achieve the determination of 27 pyrethroid pesticide residues in soils and sediments. The chromatographic conditions of the target analytes were optimized,which were extracted by acetone-hexane( V∶ V = 1∶ 1) at temperature of 120 ℃,pressure of 10. 3 MPa and extraction time of 7 minutes for 3 cycles,purified by carb/NH2 solid phase extraction cartridges,and then separated by HP-5 MS UI column. The limits of detection for this method were determined to be 0. 001 ~ 0. 012 mg/kg. The recoveries of low-and highconcentration soil spiked samples were in the range of 68. 3% ~ 123% and 75. 3% ~ 115%,respectively,and those of spiked sediment samples were 67. 1% ~ 120% and 78. 6% ~ 110%,respectively,with relative standard deviation lower than 20% for each individual target analyte( n = 6). The method developed herein is suitable for the determination of pyrethroid pesticide residues in soils and sediments,with advantages of less solvent consumption,high efficiency,low detection limit,good precision and accuracy.