| This dissertation represents two studies of some environmentally significant compounds. In the first project, coupled gas chromatography/ion trap mass spectrometry (GC/ITMS) was used to study differentiation of dimethylnaphthalene (DMN) isomers. In the second project, a crosslinked poly(vinyl pyridine) (PVP) sorbent was used for normal phase solid phase extraction (SPE) of chlorophenols and hydroxylated polychlorobiphenyls (PCB-OHs) from less polar interferences.; After a general introduction in chapter I, chapter II describes the first project. It is well recognized that alkylated polynuclear aromatic hydrocarbons (PAHs) including DMN isomers are more toxic and have a greater risk to human health than the unalkylated PAHs, due to ease of oxidation. Different isomers may have different toxicity, so the isomeric identification is an important issue in environmental analytical chemistry. The identification of DMN isomers is a challenge, because some of the isomers co-elute or partially overlap on GC, and all the isomers have identical EI full scan mass spectra. In this study, DMN isomers were differentiated into two subgroups by GC IT MS/MS: in Group I, the methyl groups are on the same ring, and in Group II, the methyl groups are on different rings. This differentiation depends on the intensity ratio of ions [M – CH3]+ / M+. or [M – 3H]+ / [M – CH3]+. The quantitative determination of some co-eluted DMN isomers was achieved with GC/MS/MS methods.; Chapter III describes separation of chlorophenols and PCB-OHs from chlorobenzenes and PCBs, respectively, using normal phase SPE with a highly cross-linked PVP sorbent. PCB-OHs are estrogen mimics in mammals including humans. Thus separation of PCB-OHs and other phenolic compounds is an important issue. SPE is faster, uses less solvent, and saves money, compared to traditional liquid-liquid extraction. For concentrating or separating chlorophenols and PCB-OHs from organic extracts of soil, sludge and sediment, normal phase SPE with polar sorbents such as silica may be needed. However, elution of these compounds is often difficult. In the separation of chlorophenols and PCB-OHs from less polar interfering compounds such as chlorobenzene and PCBs, the PVP sorbents have better selectivity, easier elution and higher adsorption capacity of phenolic compounds than silica sorbents. |
