Oil spill source identification by comprehensive two-dimensional gas chromatography

Comprehensive two-dimensional gas chromatography (GC x GC) with flame ioniz ation detection has been applied to oil spill source identification. An oil spill case from the U.S. Coast Guard's Marine Safety Laboratories (MSL) wa s analyzed by GC x GC. A slightly weathered, marine diesel fuel spill sampl e was qualitatively and quantitatively compared to two potential source sam ples. The high resolving power of GC x GC separated several hundred compone nts from the petroleum matrix. Compounds of similar chemical structure were grouped together in an ordered two-dimensional chromatogram. In these orde red groups, numerous small peaks representing minor components were separat ed and detected. This was especially helpful in determining compounds and c ompound classes to be used in the analysis. Several classes of compounds we re found to be useful for comparing the samples, including alkanes, cycloal kanes, alkylbenzenes, alkylnaphthalenes, and anthracene/phenanthrenes. The GC x GC analysis resulted in a match between the spill sample and one of th e source samples. This result was consistent with HRGC and. GC/MS analyses employed by the MSL.