GC-Q-TOF/MS快速筛查测定半夏中322种农药及化学污染物残留

Rapid Screening and Quantitative Analysis of 322 Pesticide Residues in Pinellia by Gas Chromatography-Quadruple Time of Flight Mass Spectrometry

利用GC-Q-TOF/MS检测技术,采用分散固相萃取(DSPE)样品前处理方法,建立了半夏中322种农药及化学污染物残留的筛查方法。探究了样品前处理过程中提取溶剂、缓冲盐体系、净化剂组成和用量对样品提取、净化等方面的影响,最终确定用1%的乙酸乙腈溶液和乙酸-乙酸钠缓冲体系进行提取,复合净化剂净化,GC-Q-TOF/MS测定的筛查方法。结果显示,322种农药及化学污染物中84.2%的化合物筛查限为5μg/kg,14.6%农药及化学污染物的筛查限为10μg/kg;在10,50,100μg/kg的添加水平下,农药及化学污染物的平均回收率分别为70.2%~119.5%,70.6%~119.8%,70.2%~119.9%,相对标准偏差(RSD)分别为0.2%~19.7%,0.2%~19.5%,0.5%~20.0%。与传统的分散固相萃取方法相比,该方法高效、快速,灵敏度高,准确性好,适用于半夏中322种农药及化学污染物残留的快速筛查和定量分析。

An analytical method for the simultaneous determination of 322 pesticides and chemical pollutants in Pinellia was established based on optimized dispersive solid phase extraction sample preparation method with gas chromatography-quadruple time of flight mass spectrometry（GC-Q-TOF/MS）.The influences of different extraction solvents,buffer salt systems and purifing agents on the recoveries of pesticides and chemical pollutants were investigsted.The pesticides and chemical pollutants in the samples were extracted with acetonitrile containing 1% acetic acid and acetic acid-sodium acetate，then cleaned up with mixed sorbents and analyzed by GC-Q-TOF/MS under TOF mode.The results showed that 84.2% of the 322 pesticides and chemical pollutants were limited to 5μg/kg and 14.6% of the pesticides and chemical pollutants were screened to 10 μg/kg. The recoveries at the spiked levels of 10，50,100 μg/kg were in the ranges of 70.2%-119.5%,70.6%-119.8% and 70.2%-119.9%, respectively. The relative standard deviations（RSD） were 0.2%-19.7%,0.2%-19.5% and 0.5%-20.0%，respectively. Compared to the original DSPE method,the proposed method was more efficient,rapid,sensitivie and accurate. It is suitable for the rapid screening and quantitative analysis of 322 pesticide residues and chemical pollutants in Pinellia.