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Quantitation of PAHs in Used Engine Oil Using GCxGC and Time-of-Flight Mass Spectrometry

This application note describes how using a combination of GCxGC and TOFMS PAHs are separated from matrix interferences using both orthogonal column phase selectivity and additional extracted ion mass precision.

Peak tailing and internal standard reproducibility often make quantitative analysis of polycyclic aromatic hydrocarbons (PAHs) particularly challenging. The addition of a complex matrix only makes experiments even more problematic. These difficulties are inherent to characterizing PAH levels in samples of used engine oils, which not only gives insight into engine combustion efficiencies, but also helps ensure proper environmentally-conscious waste disposal.

Identification of specific compounds is accomplished by retention time correlation with standard mixes and full-mass range spectral matching with commercial libraries. With common quantitation challenges overcome, PAH levels in used engine oils are compared between gasoline-powered engines in cars that routinely travel short vs. long distances, providing insight into the nature of combustion by-products that occur when engines are routinely operated under different conditions.