
83Used Lubricating Oils
undecanoic acid. FTIR bands at 1704 to 1603 cm
−1
were related to the presence of
carbonyl groups, and bands at 869, 813, and 1603 cm
−1
were associated with new
aromatic hydrocarbons including polycyclic aromatic hydrocarbons. NMR analysis
revealed new peaks in the used oil in the ranges of 2.1 to 2.7 and 6.8 to 7.2 parts per
million (ppm), which were associated with new aliphatic and aromatic hydrocarbon
products, respectively. FTIR and GC-MS analysis of weathered used oil indicated
the presence of various alcohols, aldehydes, and ketones, indicating substantial bio-
logical and chemical decomposition (Dominguez-Rosado ...