GC-MS法检测牛肉中拟除虫菊酯的残留量

Determination of Pyrethroid Residue in Beef by GC-MS

建立了柱层析法／气相色谱（GC）-负化学离子源（NCI）质谱检测牛肉中7种常用拟除虫菊酯杀虫剂残留的方法。样品经乙腈提取，通过中性氧化铝层析柱净化后，再由气相色谱-负化学离子源质谱选择离子监测技术（SIM）进行测定。7种菊酯类农药标准溶液在10～1000μg／L范围内线性关系良好，r^2均大于0．997。在10、20、50Ixg／kg加标水平下的回收率为80％～108％，相对标准偏差（RsD）不高于12．5％。结果表明，方法的选择性高，分离效果好，其检出限（LOD）为0．10—2．5μg/kg，定量下限（LOQ）为0．50—5．0μg／kg。

A gas chromatography （ GC ） - negative chemical ionization - mass spectrometric （ NCI/ MS ） method was established for the determination of 7 frequently used pyrethroid insecticides residues in beef. The sample was extracted with acetonitriles and cleaned up with neutral alumina chromatographic column, and then determined by GC - MS under the selected ion monitoring mode （SIM）. Good accuracy, precision and sensitivity were obtained. The calibration curves of 7 pyrethriods were linear between peak areas＇and concentrations in the range of 10 - 1 000μg/L with correlation coefficients（r2） more than 0. 997. The recoveries of 7 pyrethriods were in the range of 80% -108% at three spiked concentration levels of 10, 20, 50 μg/kg, with relative standard deviations （RSDs） less than 12.5%. The limits of deteetion（LOD） for all pyrethroid ranged from 0. 10 μg/kg to 2. 5 p,g/kg and the limits of quantitation（LOQ） were in the range of 0. 50 -5.0 μg/kg.