Quantitative determination of BTEX and total aromatic compounds in gasoline by comprehensive two-dimensional gas chromatography (GC x GC)

Comprehensive two-dimensional gas chromatography (GC x GC) has been applied to the quantitative analysis of benzene, toluene, ethylbenzene, xylenes (BTEX), and all heavier aromatic compounds in gasoline. The two-dimensional chromatographic separation used volatility selection on the first-dimension column and polarity selection on the second-dimension column. In the resulting GC x GC chromatogram, aromatic species were resolved from other compound classes. Moreover, structurally related aromatics were grouped in a manner that facilitated identification and integration, The response of a flame ionization detector to each major aromatic group in gasoline was calibrated using internal standards. Quantitation produced results directly comparable with ASTM standard methods. The present GC x GC method can be expanded to analyze other gasoline components.