Determination of naphthenic acids in crude oils using nonaqueous ion exchange solid-phase extraction

A method is presented for the routine, rapid, and quantitative analysis of aliphatic and naphthenic acids in crude oils, based on their isolation usin g nonaqueous ion exchange solid-phase extraction cartridges. The isolated a cid fractions are methylated and analyzed by gas chromatography and gas chr omatography/mass spectrometry The method is effective on both light and hea vy oils and is capable of providing mechanistic information of geochemical significance on the origin of the acids in the oils. Analysis of oils that were solvent extracted from laboritory and field mesocosm marine sediment o il degradation studies indicate that this new method of analyzing the produ cts of hydrocarbon biodegradation may be a useful tool for monitoring the p rogress of bioremediation of oil spills in the environment.