Development of Aerosol Sample Introduction Interface Coupled with ICP-MS for Direct Introduction and Quantitative Online Monitoring of Environmental Aerosol

摘要

Although much progress has been made on single particle analysis by inductively-coupled plasma-mass spectrometer (ICP-MS), many problems remain for online analysis of environmental aerosol by ICP-MS, such as aerosol direct introduction and response time. In this article, an aerosol sample introduction interface coupled with ICP-MS for direct introduction and quantitative online monitoring of environmental aerosol has been developed and characterized. Through the interface, sampling of environmental aerosol, matching of the sampling aerosol flow and the finally introduced flow, conversion of carrier gas from air-to-air-argon mixture, removal of water vapor and matrix gas, could all be implemented. Moreover, it supports the standard solution nebulization and addition method by which the transport efficiency and the instrumental sensitivity are calibrated totally in real time. Online analytical performance of ICP-MS coupled with the interface was evaluated. Results show that the response time for online monitoring of environmental aerosol improves dramatically as the aerosol sampling flow increases from 100 mL/min to 1 L/min. The sensitivity is improved through condensation growth and concentration enrichment process. The background equivalent concentration of ~(238)U in aerosol is 1.1 x 10~(-9) g/m~3. As a preliminary comparison study, uranium concentration in environmental aerosol in a clean room was monitored by online and offline methods.