Analysis of organic acids in crude oil by comprehensive two-dimensional gas chromatography and time-of-flight mass spectrometry

The composition of organic acids in crude oil samples was determined using comprehensive two-dimensional gas chromatography and time-of-flight mass spectrometry (GC×GC-TOFMS) for the first time by analyzing the deviations of acidic components in crude oil. Aliphatic acids (straight chain monocarboxylic acid, isoprenoid acid, 2-ethyl alkanoic acid methyl esters and straight chain dicarboxylic acid) and naphthenic acids (monocyclic long chain aliphatic acid, 1,4-dimethoxyanthracene, dehydroabietic acid and steroid acid) were detected in crude oil. GC×GC-TOFMS provides a new high resolution geochemical analysis of petroleum acid compositions.