用于离子迁移率谱仪的封闭式解吸电喷雾电离源研究

摘要

将解吸电喷雾电离(DESI)与离子迁移率谱(IMS)联用,快速检测农产品表面的有机磷农药残留.为减小干扰,设计并搭建了封闭式DESI电离源.对系统中电喷针与基底间距、鞘气流量、辅助电极电位、漂移管温度等参数进行优化.使用优化后的参数,实现对玻璃片和加标大白菜表面微量马拉硫磷的直接检测.系统对玻璃片和大白菜表面马拉硫磷的检测限分别为0.47 ng和8.2 ng,检测时间约10 s.%A desorption electrospray ionization(DESI)ion mobility spectrometer(IMS)was used to detect organophosphorus pesticides on the surface of agricultural products .An enclosed DESI source was designed and set up to reduce the influence of en-vironmental atmosphere.Parameters of the system,such as distance from sprayer to sample surface ,sheath gas flow rate,auxiliary electrode voltage and drift tube temperature ,were optimized .Trace malathion on the surface of glass and spiked cabbage was de-tected without sample pretreatment .The detection limits of malathion on the surface of glass andcabbage are 0.47 ng and 8.2 ng. The time of detection is about 10 seconds.