A diffusion denuder for the measurement of semivolatile organic compounds in ambient air

Thesis/Dissertation · Fri Jan 01 04:00:00 EST 1993

OSTI ID:7203888

Krieger, M S

Semivolatile organic compounds, such as polychlorinated biphenyls and polycyclic aromatic hydrocarbons, are present in the atmosphere in the gas phase and adsorbed to particles. Their atmospheric fate and transport is controlled by their partitioning between these two phases. Therefore, the accurate determination of this partitioning is important in understanding their movement through the atmosphere and their ultimate fate. Current air sampling techniques probably do not give accurate gas-particle partitioning data because of sampling artifacts inherent in the sampling process. An alternative sampling process, based on a diffusion denuder, was developed. A diffusion denuder is a tube or set of tubes through which an atmospheric sample is passed. The inside of the tube(s) is coated with a material which collects the components of interest. The authors' denuder uses capillary gas chromatographic columns as the sampling tubes. Diffusion denuders are not susceptible to the sampling artifacts that are encountered with current air sampling techniques because they collect gas-phase molecules before collection of particles. The denuder was used to collect semivolatile organic compounds from a variety of samples, including diesel exhaust, wood smoke, tobacco smoke, indoor air, and ambient air. Results from the indoor air samples demonstrate the effectiveness of on-line thermal desorption. Indoor air and ambient air measurements demonstrate that the air concentrations measured with the denuder were not different from those measured with conventional samplers. Results from combustion samples and from scanning electron microscopy indicated that particle transmission through the denuder was acceptable. Finally, the gas-particle partitioning of fourteen polycyclic aromatic hydrocarbons was measured in Indianapolis, Indiana, using the denuder. Comparable heat of desorption values to those determined by conventional sampling methods were obtained.

• Research Organization: Indiana Univ., Bloomington, IN (United States)
• OSTI ID: 7203888
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
540120* -- Environment
Atmospheric-- Chemicals Monitoring & Transport-- (1990-)
AEROSOLS
AIR
AIR POLLUTION MONITORING
AIR SAMPLERS
CHEMICAL ANALYSIS
COLLOIDS
DESIGN
DISPERSIONS
ECOLOGICAL CONCENTRATION
ENVIRONMENTAL TRANSPORT
EQUIPMENT
EXHAUST GASES
FLUIDS
GASEOUS WASTES
GASES
MASS TRANSFER
MATTER
MONITORING
ORGANIC COMPOUNDS
QUANTITATIVE CHEMICAL ANALYSIS
RESIDUES
SAMPLERS
SMOKES
SOLS
VOLATILE MATTER
WASTES