分子印迹固相萃取-液相色谱质谱联用对4种磺酰脲类除草剂残留的测定

采用苄嘧磺隆分子印迹固相萃取柱(MISPE)对加标大米中的苄嘧磺隆、甲磺隆、苯磺隆和烟嘧磺隆4种磺酰脲类除草剂进行净化和富集预处理,并采用LC-MS方法进行定量分析.质谱条件为:正离子检测模式(M+H),检测质量范围为m/z 200 ～800 ,毛细管电压3.93 kV,锥孔电压20 V,脱溶剂温度250 ℃,辅助气流速4 L/min.4种磺酰脲类除草剂在0.01 ～0.70 mg·L~(-1)范围内线性良好.回收率为68% ～100%,表明样品液中的烟嘧磺隆、甲磺隆、苯磺隆和苄嘧磺隆能直接被分子印迹固相萃取柱中的印迹位点保留,而杂质几乎不被保留.分子印迹固相萃取柱对磺酰脲类除草剂表现出良好的识别性能.

Determination of Four Sulfonylurea Herbicides Residues by High Performance Liquid Chromatography-Mass Spectrometry with Molecular Imprinting Solid Phase Extract

The pre-treatment methodology of purification and preconcentration of four sulfonylurea herbicides,including bensulfuron-methyl(BSM),metsulfuron-methyl(MSM),nicosulfuron(NS)and tribenuron-methyl(TBM) in spiked rice samples were developed using BSM molecular imprinting polymers solid phase extraction(MISPE)cartridges prepared by using the molecular imprinted polymer(MIP)as the sorbent.The MIP was prepared using the BSM as template molecule,trimethylolpropane trimethacrylate(TRIM) ∶ divinyl benzene(DVB)(1 ∶ 1) as the cross-linker,dichloromethane as porogen.The MISPE extraction procedure has been optimized.The quantitative analysis of four herbicides was performed by liquid chromatography-mass spectrometry under positive ion mode.The calibration curves were linear for four sulfonylurea herbicides in the concentration range of 0.01-0.70 mg·L~(-1) and the recoveries from spiked rice samples were between 68% and 100%.The result indicated that except the interferents,the sulfonylurea herbicides of BSM,MSM,NS and TBM were strongly retained by the imprinting sites in BSM molecular imprinting polymers SPE cartridges.The MIP showed high selective recognition and affinity to four sulfonylurea herbicides.