An automated online field instrument to quantify the oxidative potential of aerosol particles via ascorbic acid oxidation

Large-scale epidemiological studies have consistently shown that exposure to ambient particulate matter (PM) is responsible for a variety of adverse health effects. However, the specific physical and chemical properties of particles that are responsible for the observed health effects, as well as th...

Full description

Saved in:

Bibliographic Details
Published in:	Atmospheric measurement techniques Vol. 16; no. 10; pp. 2641 - 2654
Main Authors:	Utinger, Battist, Campbell, Steven John, Bukowiecki, Nicolas, Barth, Alexandre, Gfeller, Benjamin, Freshwater, Ray, Rüegg, Hans-Rudolf, Kalberer, Markus
Format:	Journal Article
Language:	English
Published:	Katlenburg-Lindau Copernicus GmbH 30-05-2023 Copernicus Publications
Subjects:	Aerosol concentrations Aerosol particles Aerosols Air pollution Analysis Antioxidants Ascorbic acid Biocompatibility Chemical properties Chemicophysical properties Chemistry Components Epidemiology Health aspects Health risks Hydrochloric acid In vivo methods and tests Labour Measurement methods Metals Outdoor air quality Oxidation Oxidative stress Particulate emissions Particulate matter Pollution Scale (corrosion) Suspended particulate matter Time lag Toxicity Urban environments Vitamin C
Online Access:	Get full text
Tags:	Add Tag No Tags, Be the first to tag this record!

Description
Summary:	Large-scale epidemiological studies have consistently shown that exposure to ambient particulate matter (PM) is responsible for a variety of adverse health effects. However, the specific physical and chemical properties of particles that are responsible for the observed health effects, as well as the underlying mechanisms of particle toxicity upon exposure, remain largely uncertain. Studies have widely suggested that the oxidative potential (OP) of aerosol particles is a key metric to quantify particle toxicity. OP is defined as the ability of aerosol particle components to produce reactive oxidative species (ROSs) and deplete antioxidants in vivo. Traditional methods for measuring OP using acellular assays largely rely on analyzing PM collected in filters offline. This is labor intensive and involves a substantial time delay between particle collection and OP analysis. It therefore likely underestimates particle OP because many reactive chemical components which contribute to OP are short-lived and therefore degrade prior to offline analysis. Thus, new techniques are required to provide a robust and rapid quantification of particle OP, capturing the chemistry of oxidizing and short-lived, highly reactive aerosol components and their concentration dynamics in the atmosphere. To address these measurement shortcomings, we developed a portable online instrument that directly samples particles into an ascorbic acid-based assay under physiologically relevant conditions of pH 6.8 and 37 .sup." C, providing continuous, accurate OP measurements with a high time resolution (5 min). The instrument runs autonomously for up to 3 d and has a detection limit of about 5 Âµg m.sup.-3 in an urban environment, which allows the characterization of particle OP even in low-pollution areas.
ISSN:	1867-1381 1867-8548
DOI:	10.5194/amt-16-2641-2023