在中国，毒死蜱作为替代高毒有机磷农药的最佳选择之一，已被广泛用于控制蔬菜生产过程中病虫害，然其带来的食品安全问题引起了人们越来越多的关注，因此建立快速检测毒死蜱残留的新方法显得尤为重要。本研究构建了一种改进的QuEChERS样品预处理和气相色谱-质谱(GC-MS)联用法，以快速测定白菜叶际毒死蜱的残留量。样品用含1%乙酸的乙腈提取，用适量N-丙基乙二胺(PSA)、无水MgSO4、石墨化炭黑(GCB)和C18填料净化，GC-MS检测，外标法定量。结果表明：毒死蜱在质量浓度为0.20~1.00 mg/L时，线性关系良好，R大于0.999；添加水平为0.10~0.50 mg/kg时，平均回收率为72.00%~111.00%，相对标准偏差为1.30%~1.60%，检出限(LOD)为0.005 mg/kg，定量限(LOQ)为0.01 mg/kg。该方法简便、快速、准确、灵敏，能够满足白菜叶际毒死蜱残留的定性和定量分析检测。枯草芽胞杆菌3374对白菜叶际毒死蜱残留具备有效降解能力。

In China, chlorpyrifos, as one of the most suitable pesticides to replace the highly toxic organophosphorus pesticides, has been widely used to control pests and diseases in vegetable production. However, the food safety problems brought by chlorpyrifos have attracted more and more attention. Therefore, it is very important to establish new methods for rapid detection of chlorpyrifos residues. In this study, an improved method, QuEChERS sample pretreatment coupled to gas chromatography-mass spectrometry (GC-MS) has been developed for rapid detection of the residual amount of chlorpyrifos on the phyllosphere of Brassica chinensis. The sample was extracted with acetonitrile containing 1% acetic acid, and purified with an appropriate amount of N-propyl Ethylenediamine(PSA), anhydrous magnesium sulfate, graphitized carbon black(GCB) and C18 filler, before analysis by gas chromatography-mass spectrometry and quantification with external standards. The obtained results showed a good linear relationship in the concentration range of 0.20~1.00 mg/L with correlation coefficients greater than 0.999. When the spiked level was 0.10~0.50 mg/kg, the average recoveries of chlorpryrifos were 72.00%~111.00%, with the relative standard deviations as 1.30%~1.60%, limit of detection (LOD) as 0.005 mg/kg, and limit of quantitation (LOQ) as 0.01 mg/kg. The established method is simple, rapid, accurate and sensitive, and can meet the requirements for qualitative and quantitative analysis of the residues of chlorpyrifos on the phyllosphere of Brassica chinensis. Bacillus subtilis 3374 could degrade effectively the chlorpyrifos residues on the phyllosphere of Chinese cabbage.

国家自然科学基金面上项目(31570494)；国家留学基金委项目(201708110129)；北京市自然科学基金项目(6173033)；校级科技成果转化培育项目（22213591113/001）