CaltechAUTHORS
  A Caltech Library Service

Sampling Atmospheric Carbonaceous Aerosols Using a Particle Trap Impactor/Denuder Sampler

Mader, Brian T. and Flagan, Richard C. and Seinfeld, John H. (2001) Sampling Atmospheric Carbonaceous Aerosols Using a Particle Trap Impactor/Denuder Sampler. Environmental Science and Technology, 35 (24). pp. 4857-4867. ISSN 0013-936X. https://resolver.caltech.edu/CaltechAUTHORS:20150818-100012364

Full text is not posted in this repository. Consult Related URLs below.

Use this Persistent URL to link to this item: https://resolver.caltech.edu/CaltechAUTHORS:20150818-100012364

Abstract

A particle trap impactor/denuder system has been developed and tested for the sampling of ambient carbonaceous aerosols. Use of a particle trap impactor allows for a reduction of particle bounce and re-entrainment at high particle loadings, and operation at high volumetric flow rates is achieved without the use of oiled impaction substrates, thus facilitating the chemical and physical analysis of the organic compounds comprising the collected gas (G) and particle (P) phases. Honeycomb denuders have a greater density of channels for a given denuder cross-sectional area than parallel plate or annular denuders; for a given sampling flow rate, honeycomb denuders can be fabricated in more compact shapes and will have a greater amount of surface area for the collection of gases. Field testing of the sampler was conducted primarily at night to minimize the evaporation of organic carbon (OC) from collected particles, which can result from the heating of collected particles as ambient temperatures rise during the day. In side-by-side testing with an open-face filter pack sampler, the denuder system was found to minimize positive gas adsorption artifacts caused by the adsorption of gaseous OC to quartz filter fiber (QFF) surfaces. In the denuder sampler, negligible amounts of OC were observed on a QFF placed downstream of a particle-loaded QFF, suggesting that OC detected on the backup QFF in the filter pack sampler resulted primarily from the adsorption of ambient G-phase OC rather than OC evaporated from particles collected on the front filter. Equations are presented for the evaluation of the magnitude of positive and negative sampling artifacts. Analysis of these equations indicates that the mass of OC evaporated from filter-bound particles present downstream of a denuder depends on (i) the volume of OC-free gas passed through the filter, (ii) the P-phase concentration and the P/G partition coefficients (K_p) of the compounds comprising the P-phase OC, (iii) the temperature (T) (values of K_p are inversely proportional to T), and (iv) the mass fraction of carbon in the compounds comprising P-phase OC. For these reasons, the magnitude of evaporative losses of OC in denuder samplers may vary among different sampling events. In addition, a method utilizing gas chromatography/mass spectrometry has been developed for determination of inertial impactor collection efficiency and denuder particle transmission efficiency. Using this method, only a single extraction of the sampler components is necessary, thereby reducing the number of extractions and analyses over conventional approaches by at least a factor of 2.


Item Type:Article
Related URLs:
URLURL TypeDescription
http://dx.doi.org/10.1021/es011059oDOIArticle
http://pubs.acs.org/doi/abs/10.1021/es011059oPublisherArticle
ORCID:
AuthorORCID
Flagan, Richard C.0000-0001-5690-770X
Seinfeld, John H.0000-0003-1344-4068
Additional Information:© 2001 American Chemical Society. Received for review June 12, 2001. Revised manuscript received September 10, 2001. Accepted September 18, 2001. This work was supported by Office of Naval Research Grant N00014-96-0119 and National Science Foundation Grant ATM-0001934.
Funders:
Funding AgencyGrant Number
Office of Naval Research (ONR)N00014-96-0119
NSFATM-0001934
Issue or Number:24
Record Number:CaltechAUTHORS:20150818-100012364
Persistent URL:https://resolver.caltech.edu/CaltechAUTHORS:20150818-100012364
Official Citation:Sampling Atmospheric Carbonaceous Aerosols Using a Particle Trap Impactor/Denuder Sampler Brian T. Mader, Richard C. Flagan, and John H. Seinfeld Environmental Science & Technology 2001 35 (24), 4857-4867 DOI: 10.1021/es011059o
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:59677
Collection:CaltechAUTHORS
Deposited By: Irina Meininger
Deposited On:20 Aug 2015 20:37
Last Modified:03 Oct 2019 08:49

Repository Staff Only: item control page