Development and Evaluation of a High-Volume Aerosol-into-Liquid Collector for Fine and Ultrafine Particulate Matter

Abstract

This study presents a novel high-volume aerosol-into-liquid collector, developed to provide concentrated slurries of fine and/or ultrafine particulate matter (PM) to be used for unattended, in situ measurements of PM chemistry and toxicity. This system operates at 200 liters per minute (L/min) flow and utilizes the saturation-condensation, particle-to-droplet growth component of the versatile aerosol concentration enrichment system (VACES), growing fine or ultrafine PM to 3-4-μm droplets, in conjunction with a newly designed impactor, in which grown particles are collected gradually forming highly concentrated slurries. Laboratory evaluation results indicated an excellent overall system collection efficiency (over 90%) for both monodisperse and polydisperse particles in the range of 0.01 to 2 μm. Field evaluations illustrated that overall a very good agreement was obtained for most PM 2.5 species between the new aerosol collection system and the VACES/BioSampler tandem as well as filter samplers operating in parallel. Very good agreement between the new system and the VACES/BioSampler was also observed for reactive oxygen species (ROS) in ambient PM 2.5 samples, whereas lower ROS values were obtained from the water extracts of the filter, likely due to incomReceived 15 May 2013; accepted 17 July 2013. The authors would like to thank Dr. Massoud Pirbazari and Woonhoe Kim (USC) for their assistance in the chemical analysis. This study has been supported by the South Coast Air Quality Management District (AQMD) through award number #11527 and the National Institutes of Health (NIH) through Grants R01AI065617-13 and R21AG040753-02 to the University of Southern California (USC). The research described herein has not been subjected to the agency's required peer and policy review and, therefore, does not necessarily reflect the views of the agency, and no official endorsement should be inferred. Mention of trade names or commercial products does not constitute an endorsement or recommendation for use.Address correspondence to Constantinos Sioutas, Department of Civil and Environmental Engineering, University of Southern California, 3620 S. Vermont Ave., 216C Kaprielian Hall, KAP 216C, M/C 2531, Los Angeles, CA 90089, USA. E-mail: sioutas@usc.edu plete extraction of water insoluble redox active species collected on the filter substrate. Moreover, the field tests indicated that the new aerosol collection system could achieve continuous and unattended collection of concentrated suspensions for at least 2 to 3 days without any obvious shortcomings in its operation. Both laboratory and field evaluations of the high-volume aerosol-into-liquid collector suggest that this system is an effective technology for collection and characterization of ambient aerosols.

A new technique for online measurement of total and water-soluble copper (Cu) in coarse particulate matter (PM)

“…Recently, an online Cu monitor was described to achieve near-continuous measurements of total and water-soluble Cu in fine particles (PM 2.5 ) (Wang et al, 2014). This system utilizes a newly developed Aerosol-Into-Liquid Collector (Wang et al, 2013a) as the PM collection module and a copper ion selective electrode (ISE) as the Cu measurement module. In the Aerosol-Into-Liquid Collector, ambient fine PM are first grown to 3e4 mm droplets through a saturation-condensation process, and are then sequentially collected in a high flow rate (i.e.…”

Prototype Development and Laboratory Evaluation of an Aerosol to Hydrosol Sampler

“…Moreover, long sampling times may lead to a loss of volatile components in collected particles (Chow, 1995). Thus, the measurements obtained through filter sampling cannot fully describe the changes in aerosol chemistry in the way possible with high time resolution sampling methods (Orsini et al, 2003;Wang et al, 2013). In addition, the high loading of filters may allow for chemical reactions to occur on the filter, resulting in loss or changes in composition.…”

“…However, the system is large and not suitable for field deployment and sampling. Wang et al (2013) introduced a high volume aerosol into liquid collector. It samples at a flow rate of 200 L/min and uses a condensational growth component of versatile aerosol concentration enrichment system (VACES) (Kim et al, 2001).…”

Improved Time-Resolved Measurements of Inorganic Ions in Particulate Matter by PILS-IC Integrated with a Sample Pre-Concentration System

“…First, the dilution of the sample by the washing solution leads to high detection limits, which make the system unsuitable for low-polluted areas (Wang et al 2013). Most important, the time coverage is low (about 2-5 min per hour), as only the sample amount contained inside the loop at the time of the injection is analyzed, while the sample amount collected during the time of the analysis is discarded.…”