Rapid analysis of the size distribution of metal-containing aerosol

Abstract

Conventional methods to measure the metallic content of particles by size are time consuming and expensive, requiring collection of particles with a cascade impactor and subsequent metals analysis by inductively coupled plasma mass spectrometry (ICP-MS). In this work, we describe a rapid way to measure the size distribution of metal-containing particles from 10 nm to 20 µm, using a nano micro-orifice uniform-deposit impactor (nano-MOUDI) to size-selectively collect particles that are then analyzed with a field portable X-ray fluorescence (FP-XRF) device to determine metal composition and concentration. The nano-MOUDI was used to sample a stainless-steel aerosol produced by a spark discharge system. The particle-laden substrates were then analyzed directly with FP-XRF and then with ICP-MS. Results from FP-XRF were linearly correlated with results from ICP-MS (R2 = 0.91 for Fe and R2 = 0.84 for Cr). Although the FP-XRF was unable to effectively detect Fe particles at mass per substrate loadings less than 2.5 µg effectively, it produced results similar to those from ICP-MS at a mass per substrate loadings greater than 2.5 µg. Copyright © 2017 American Association for Aerosol Research