"The carboxylic acid produced from the reaction of Green River oil shale kerogen with carbon monoxide and water at temperatures of 300- 450°C were investigated. The acid were eterifled with diazomethane, and the acid esters were separated by chromatographic techniques into two fraction : -n-saturated and branched-plus-cyclic saturated acid ester fractions, Gas chromatography (GC) and gas chromatography-ma 's spectrometry (GC-M ) analyses of the n-saturated fractions showed the presence of carboxylic acids of CI4 to C)4 chain length. and the even odd predominance (EO?) was high in fractions produced below 450° C. Isoprenoid saturated acid and terpenoid saturated acid compounds in the branched-plus -cyclic saturated acid fraction predominated at 300°C but decreased tremendously at 450° C. The results of this study show that structures containing carboxyl groups are major components of Green River oil shale kerogen ."