Quantification of Element Mass Concentrations in Ambient Aerosols by Combination of Cascade Impactor Sampling and Mobile Total Reflection X-ray Fluorescence Spectroscopy

Stefan Seeger,Yves Kayser,Francois Gaie-Levrel,Maria Ochsenkuehn-Petropoulou,Markus Fiebig,Theopisti Lymperopoulou,Hagen Stosnach,Luca Stabile,Lamprini Areti Tsakanika,Janos Osan,Armin Gross,Sharon Goddard,Burkhard Beckhoff,Ottó Czömpöly

doi:10.3390/atmos12030309

Abstract

Quantitative chemical analysis of airborne particulate matter (PM) is vital for the understanding of health effects in indoor and outdoor environments, as well as for enforcing EU air quality regulations. Typically, airborne particles are sampled over long time periods on filters, followed by lab-based analysis, e.g., with inductively coupled plasma mass spectrometry (ICP-MS). During the EURAMET EMPIR AEROMET project, cascade impactor aerosol sampling is combined for the first time with on-site total reflection X-ray fluorescence (TXRF) spectroscopy to develop a tool for quantifying particle element compositions within short time intervals and even on-site. This makes variations of aerosol chemistry observable with time resolution only a few hours and with good size resolution in the PM10 range. The study investigates the proof of principles of this methodological approach. Acrylic discs and silicon wafers are shown to be suitable impactor carriers with sufficiently smooth and clean surfaces, and a non-destructive elemental mass concentration measurement with a lower limit of detection around 10 pg/m3 could be achieved. We demonstrate the traceability of field TXRF measurements to a radiometrically calibrated TXRF reference, and the results from both analytical methods correspond satisfactorily.

Highlights

Airborne particulate matter (PM) is a harmful atmospheric pollutant, due to the size and chemistry of the particles
While preliminary results were initially obtained using the 50 ng Y standard for a comparison of element mass concentrations during the campaign, all data were corrected after recalibration of the S2 total reflection X-ray fluorescence (TXRF) spectrometer
It can be assumed that Cd is distributed over a broader particle size range, and the total collected masses on the impactor carriers are likely below the TXRF detection limit of approximately 0.3 ng for Cd

Summary

Introduction

Airborne particulate matter (PM) is a harmful atmospheric pollutant, due to the size and chemistry of the particles. Anthropogenic aerosols contribute to climate change and have been linked to respiratory and cardiovascular diseases, lung cancer, and several other diseases [2,3,4]. Knowledge of the chemistry of aerosols is vital for the understanding of health effects in indoor and outdoor environments. Aerosols loaded with heavy metals or other toxic elements contribute to various human health effects, ranging from cardiovascular and pulmonary inflammation to cancer and damage of vital organs even at the low concentrations found in ambient air. The smaller the size and greater the solubility of the particles, the higher the toxicity through mechanisms of oxidative stress and inflammation, prompted by the redox chemistry of these heavy metals. Further details of health effects are given, e.g., in World Health

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