Environmental sciences Air--Pollution Life Sciences
Organic compounds have become widely used as tracers for source apportionment of particulate matter. Some of the organic tracers commonly used are distributed between the gas and particle phase. Their presence in the gas phase could lead to sampling artifacts due to adsorption of vapors on collection filters, resulting in a significant bias in particle phase concentration measurements. In this study, sampling artifacts for molecular markers from organic speciation of particulate matter and their influence on source contribution estimates using the Chemical Mass Balance model were investigated. The results indicated n-alkanes (C23-C24) and n-alkanoic acids (C10-C14) were seriously affected by artifact errors, with backup fractions greater than 50% for each compound. In contrast, artifact errors for n-alkanes larger than n-heptacosane (C28), hopanes larger than 17[alpha](H), 21[beta](H)-hopane (C30) and n-alkanoic acids larger than n-octadecanoic acid (C18) appeared to be insignificant. Overall, species with low molecular weight or high vapor pressure had significant amounts of artifact on quartz fiber filters as measured using backup filters. The contribution of diesel powered vehicles and the percentage of particulate organic carbon mass accounted for was reduced after n-alkane and hopane artifact correction. There were indications that artifact correction may improve model resolution. The n-alkane artifact effect on diesel exhaust contribution suggests that source profiles that contain molecular markers with large sampling artifacts lead to overestimates of both source contributions and percentage of mass accounted for.
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Title
Sampling artifacts of particulate organic species and their effects on receptor modeling results
Creators
Tanasri Sihabut - DU
Contributors
Stephen R. McDow (Advisor) - Drexel University (1970-)
Awarding Institution
Drexel University
Degree Awarded
Doctor of Philosophy (Ph.D.)
Publisher
Drexel University; Philadelphia, Pennsylvania
Resource Type
Dissertation
Language
English
Academic Unit
Civil (and Architectural) Engineering [Historical]; College of Engineering (1970-2026); Drexel University