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

Development and field evaluation of an online monitor for near-continuous measurement of iron, manganese, and chromium in coarse airborne particulate matter (PM)

“…The developed system comprises two modules: (1) the coarse PM collection module, and (2) the metal concentration measurement module. The coarse PM collection module utilizes two virtual impactors (VIs) connected in parallel, coupled with a modified BioSampler (i.e., liquid impinger) (BioSampler, SKC West, Inc., Fullerton, CA, USA) technology, for which extensive details can be found elsewhere (Wang et al 2015). Briefly, the air is drawn into two round nozzle VIs, each having a major flow rate of 100 L/min and a minor flow rate of 5 L/min.…”

“…This total flow rate corresponds to a theoretical 50% cutpoint of 1.5 mm in aerodynamic diameter, concentrating airborne coarse PM into the VI's minor flow. As discussed in our earlier studies (Wang et al 2015), although the theoretical cut point of the VIs is slightly lower than the traditional definition of the coarse PM size range (i.e., 2.5 mm), this cut point was selected to ensure that the entire size range of ambient coarse PM is concentrated by the maximum enrichment factor of about 20. The two minor flows are combined into a total flow rate of 10 L/min entering the modified BioSampler, in which particles are captured in 20 mL of ultrapure water to form a particle-liquid suspension.…”

“…Nonetheless, the impact of individual chemical components of PM on the health end-points is still relatively poorly understood; therefore, the development of innovative PM measurement techniques capable of providing high-resolution of chemically speciated data and their use in concurrent toxicological studies can drastically improve our current understanding of the main PM species driving these health effects (Karlsson et al 1997;Weber et al 2001;Wang et al 2015). These novel techniques will also help improve our understanding of the dynamics of atmospheric PM emission, dispersion, and fate through the provision of data with higher time resolution.…”

“…A large fraction of many of these metals and trace elements is partitioned in the coarse PM fraction (Allen et al 2001), which further highlights the need for developing techniques capable of measuring coarse PM-bound redox-active metals with a high time-resolution. Such tools will be crucial in investigations of the health impacts induced by the coarse fraction of PM, as recent studies have indicated significant association between these metals and the redox activity of coarse PM (Becker and Soukup 2003;Becker et al 2005;Shafer et al 2010;Cheung et al 2011Cheung et al , 2012Wang et al 2015). To address these needs, in the present study, we developed a new technique for near-continuous (i.e., a time resolution of 2 h) measurement of three coarse PM-bound redoxactive metals, namely Fe, Mn, and Cr.…”

Atmospheric Signature and Potential Sources of Rare Earth Elements in Size-Resolved Particulate Matter in a Megacity of China

“…The measurement of the chemical constituents of ambient PM is critical to evaluate its environmental impact and potential sources (Villalobos et al, 2015). Many studies have investigated the PM chemical constituents of water soluble ions (Eleftheriadis et al, 2014;Wang et al, 2015), carbonaceous components (Cao et al, 2007;Jimenez et al, 2009), heavy metals (Basha et al, 2010;Wang et al, 2013) and polycyclic aromatic hydrocarbon (PAHs) (Gao et al, 2015;Liu et al, 2015). However, information on rare earth elements (REEs) in PM is still sparse (Griffiths, 2010).…”