差分真空单颗粒进样在线气溶胶飞行时间质谱系统的研制

Development of on-line aerosol time of flight mass spectrometry system based on the single particle inlet of differential vacuum

详细说明了差分真空单颗粒进样在线气溶胶飞行时间质谱系统(LAMPAS-3 PLUS)的单颗粒进样系统、双光束测径系统、双极飞行时间质谱仪以及数据采集分析系统,并分别用标准粒子对仪器进行粒径标定与质量峰校正。测试结果表明,仪器对0.2～2.5μm粒径段的颗粒物具有稳定的信号响应和～70%的电离效率,并且具有质谱峰识别精准漂移小的特点。仪器外场监测数据提供在线大气颗粒物粒径信息和组分信息的同时,结合模糊C均值聚类算法(FCM)与自适应共振神经网络算法(ART-2a)可实现对大气颗粒物污染来源快速解析,能够为大气颗粒物溯源解析提供重要依据。

An on-line aerosol time of flight mass spectrometry(LAMPAS-3 PLUS) system based on the single particle inlet of differential vacuum have been concretely described, which includes single particle inlet system, double-beam particle diameter measurement system, bipolar time of flight mass spectrometer and data acquisition and analysis system. The calibration of particle size and correction of mass peaks with standard particles are carried out respectively. The test results show that the instrument has stable signal response and high ionization efficiency(～70%) for the 0.2～2.5 μm particles and small drift in the identification of mass peaks. The online monitoring data provides the information of the air particles sizes and components. Combining the fuzzy C mean clustering algorithm(FCM) and the adaptive resonance neural network algorithm(ART-2 a), the pollution sources of the atmospheric particles have been analyzed online. The results show that LAMPAS-3 PLUS can provide a significant data support for the apportionment of atmospheric particles pollution.