Resolving the unresolved complex mixture in petroleum-contaminated sediments.
Comprehensive two-dimensional gas chromatography (GC x GC) was used to investigate the chemical composition of the unresolved complex mixture (UCM) of hydrocarbons in petroleum-contaminated marine sediments. The UCM hydrocarbons were extracted and separated with silica and silver-impregnated silica gel chromatography to yield four fractions (branched alkanes and cycloalkanes, monoaromatics, naphthalenes, and multi-ring PAHs) prior to GC x GC analysis. GC x GC separations used a poly-(dimethylsiloxane) stationary phase for volatility selectivity on the first dimension and a 14% cyanopropylphenyl polysiloxane phase for polarity selectivity on the second dimension to fully resolve monoaromatic, naphthalene, and multi-ring PAH compounds from the UCM. A chiral gamma-cyclodextrin phase was used for shape selectivity on the second GC x GC dimension to resolve individual branched alkanes and cycloalkanes in the saturates fraction of the UCM. The ability of GC x GC to resolve thousands of individual chemical components from the UCM will facilitate an understanding of the sources, weathering, and toxicity of UCM hydrocarbons.
Frysinger
Glenn S
GS
Department of Science, United States Coast Guard Academy, New London, Connecticut 06320, USA. gfrysinger@cga.uscg.mil
Gaines
Richard B
RB
Xu
Li
L
Reddy
Christopher M
CM
D002849:Chromatography, Gas; D004784:Environmental Monitoring / Q000379:methods*; D019015:Geologic Sediments / Q000737:chemistry*; D006838:Hydrocarbons / Q000032:analysis / Q000737:chemistry*; D010578:Petroleum; D012680:Sensitivity and Specificity; D014874:Water Pollutants, Chemical / Q000032:analysis*
D006838:Hydrocarbons; D010578:Petroleum; D014874:Water Pollutants, Chemical