10th International Aerosol Conference
September 2 - September 7, 2018
America's Center Convention Complex
St. Louis, Missouri, USA

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Direct Measurement of Trace Multi-Elemental Aerosols using Inductively Coupled Plasma Time-of-Flight Mass Spectrometry and X-ray Fluorescence Spectroscopy

HAGINO HIROYUKI, Martin Tanner, Olga Borovinskaya, Toshihide Hikita, Akio Shimono, Kohei Nishiguchi, Yusuke Mizuno, Japan Automobile Research Institute (JARI)

     Abstract Number: 18
     Working Group: Instrumentation

Abstract
Inductively coupled plasma mass spectrometry (ICP-MS) is widely used when rapid and sensitive detection for a wide range of elements of airborne particles is required in many situations, such as the monitoring of the ambient particulate matter (PM), emission sources, and the clean room air for semiconductor manufacture processes. In analysis by ICP-MS, the airborne particles are usually collected on filters and elemental analysis is carried out through pre-processing on the resultant sample, as well known as off-line analysis. This off-line analysis using ICP-MS takes time for a day or a few days, and reduces the time resolution about the behaviour of particle concentration.

For on-line and real-time analysis of aerosol samples using ICP-MS, the gas exchange devices (GED) which followed by the replacement of air with argon and transported to the ICP-MS is need to be equipped due to sustaining the plasma (Nishiguchi et al., 2008). The bulk aerosol sample were produced by a GED with ICP-MS that exchanges the gas molecules from air to Ar the resulting gas-converted air sample can be introduced directly into the ICP-MS instrument. However, the ICP-MS used a quadrupole mass spectrometer (ICP-QMS), a detailed study on the signal fine structure with scanning-based mass spectrometers but no simultaneous multi-element measurement was possible. In order to further improve time resolution of the ICP-QMS and to extend its capabilities to determine single particle information, ICP-MS equipped with the Time-of-Flight Aerosol Mass Spectrometer (ICP-TOFMS) was developed recently (e.g. Martine and Günther, 2008) and provided commercially (icpTOF, Tofwerk).

This study describes a direct trace multi-elemental aerosol measurement in which an icpTOF (Aerosol-icpTOF) has been eqipped with a GED (GEDIII, J-Science Laboratory). This Aerosol-icpTOF is the real-time, field-deployable, aerosol mass spectrometer that is capable of directly distinguishing the elemental composition of ions having the same nominal mass and will be described the more details in elsewhere (Hagino et al., In-preparation).

The trace elements in ambient PM2.5 were measured by using the Aerosol-icpTOF and the continuous particulate monitor with X-ray Fluorescence (XRF) (Model PX375, HORIBA). The icpTOF and XRF are a fundamentally different instruments. However, there were the high degree of correlation as trace element concentrations during the 1-h time resolution.