GC-MS法测定罗汉果中拟除虫菊酯农药残留量

Determination of 6 Kinds of Pyrethroid Pesticides in Siraitia Grosvenorii by GC-MS

建立气质联用(Gas chromatography-mass spectrometry,GC-MS)测定罗汉果中6种拟除虫菊酯类农药的残留量方法。样品用石油醚-丙酮混合溶剂超声提后过固相萃取小柱净化,经HP-5MS色谱柱分离,以气相色谱质谱法进行检测,用外标法计算含量。结果表明:6种拟除虫菊酯类农药在0.1μg/mL^1.0μg/mL范围内呈现良好的线性关系,相关系数为0.999 1~0.999 9,检出限为0.139μg/kg^5.262μg/kg。样品中3个加标水平的回收率为83.5%~106.1%,相对标准偏差(RSD)为0.9%~6.5%。本试验所建立的方法操作简便,具有良好的回收率,精密度和灵敏度,符合检测要求,可用于罗汉果中6种拟除虫菊酯类农药残留的测定。

The method for determination of six pyrethroid pesticides in Siraitia Grosvenorii by gas chromatography-mass spectrometry was established. The samples were extracted with organic solvent by ultrasound,and pyrethroid pesticides were cleaned-up by solid-phase extraction column,determined by GC-MS with HP-5 MS chromatographic column. The contents were calculated by the external standard method. The results showed that the linear range was from 0.1 μg/mL to 1.0 μg/mL with correlation coefficients(r = 0.999 1-0.999 9). The limits of detection were 0.139 μg/kg-5.262 μg/kg,and the average recoveries ranged from 83.5 % to 106.1 %,with the relative standard deviations from 0.9 % to 6.5 %. The proposed method is effective,quick,sensitive and reproducible,and can be applied to determine pyrethroid pesticide residues in Siraitia Grosvenorii.