Abstract
Oxidation products of young kerogens isolated from seven lake sediments were analyzed for low molecular weight acids (LMW-acids: C1〜C2 monocarboxylic and C2〜C6 α, ω-dicarboxylic acids) by GC and GC/MS. The oxidation was conducted at 60℃ in 1% potassium permanganate solution for 1h. Kerogen carbon that degraded into the solution accounted for 70〜80% of the total. 17〜28% (average 22%) of the degraded carbon were LMW-acids. Oxalic acid accounted for 83〜93% (average 90%) of the LMW-acids, the rest being mostly acetic acid. Kerogens of different lakes yielded similar results both in the amount and in the composition of LMW-acids. Oxidation products of synthetic kerogens (melanoidins form amino acids and carbohydrates) and biochemical compounds (carbohydrate, amino acids, protein, and lipids) were also studied. When compared with lake kerogens in terms of amount and composition of the resultant LMW-acids, melanoidins gave the closest result. The diagram of oxalic acid yield versus oxalic acid index (OAI: amount of oxalic acid relative to the total LMW-acids ) was proposed for estimating the source materials of kerogen.
