Date of Award
Master of Science in Chemistry - (M.S.)
Chemical Engineering, Chemistry and Environmental Science
Barbara B. Kebbekus
R. P. T. Tomkins
Two seasonal periods (Winter 1988; Summer 1988) of daily Newark urban air samples were collected on glass fiber filters. Each filter was first extracted with dichloromethane and subsequently with acetone. Quarterly composites of each were then tested for mutagenicity. The results of the analysis of the less polar dichloromethane extracts were reported in the thesis of Junghen Lwo. A modified fractionation scheme involving acid-base partitioning and silica gel column chromatography has been used as the first step in the bioassay-directed search for significant levels of mutagenic compounds in extracts of inhalable (IP 10) ambient air particulates. The biologically "hot" fractions (fractions having highest specific mutagenicities) were separated and analyzed chemically and subfractionated to isolate and concentrate "hot" subfractions which were then chemically analyzed by GC/MS and FTIR.
The Ames assay of mutagenicity has been employed using the unactivated TA98 strain of Salmonella and enzyme-activated (TA98 + S9) assays. In addition, some assays were performed in this present study using TA98NR (TA98-nitroreductase deficient) and TA98DNP (TA98-dinitropyrene reductase deficient). In essence, mutagenicity was used as the chromatographic detector to pinpoint the most active fractions and compounds which are responsible for mutagenicity (and possibly carcinogenicity) in the air, and then monitor them as well as assess their reactivity.
The comparison of winter and summer samples indicated that the mass and mutagenicity profiles were similar in the two periods. However, the most interesting result related to the acetone extract is that its weak acid fraction has the most bioactivity among all fractions and subfractions isolated from both acetone and dichloromethane extracts of the particulates.
Wu, Wenhui, "Study of acetone extractable organic matter from airborne particulate matter from an urban site" (1989). Theses. 1953.