Measurement of hourly variations of the volatile organic compounds in atmospheric aerosols

Thesis/Dissertation · Wed Jan 01 04:00:00 EST 1986

OSTI ID:6918242

Greaves, R C

Low volume sampling coupled with direct thermal desorption was used to investigate the composition of the volatile organic fraction of aerosols. Samples of suspended particles are collected for times ranging from 7 min to 9 h by filtration of between 40 and 2000 L of air through a glass tube containing a small quartz fiber filter. This collection tube is then connected directly to a cryogenically cooled fused silica capillary chromatography column into which the volatile organic compounds are rapidly thermally desorbed, at a maximum temperature of 254/sup 0/ for 15 min. As the column temperature is subsequently raised, chromatography proceeds, with detection of the desorbed organic compounds by flame ionization or mass spectroscopy. The technique exhibits good quantitative precision for polycyclic aromatic hydrocarbons and saturated n-alkanes. The method was compared with high volume sampling with solvent extraction and the two methods agreed within a factor of 1.25 for half of the hydrocarbons quantitated. Experiments were also conducted concerning the transfer of organics through the desorption apparatus, organics remaining after initial desorption, and the optimal temperature and time for thermal desorption.

• Research Organization: Colorado Univ., Boulder (USA)
• OSTI ID: 6918242
• Country of Publication: United States
• Language: English

Related Subjects

500200* -- Environment
Atmospheric-- Chemicals Monitoring & Transport-- (-1989)
54 ENVIRONMENTAL SCIENCES
AEROSOL MONITORING
AIR POLLUTION
AIR POLLUTION MONITORING
AIR SAMPLERS
ALKANES
AROMATICS
CHROMATOGRAPHY
DESIGN
ECOLOGICAL CONCENTRATION
EQUIPMENT
HOURLY VARIATIONS
HYDROCARBONS
MASS SPECTROSCOPY
MEASURING METHODS
MONITORING
ORGANIC COMPOUNDS
POLLUTION
POLYCYCLIC AROMATIC HYDROCARBONS
SAMPLERS
SEPARATION PROCESSES
SPECTROSCOPY
VARIATIONS
VOLATILITY