超临界萃取技术在泥炭纤维素提纯中的应用与萃取组分特征

Application of Supercritical Fluid Extraction Method for the Purification of Peat Cellulose and Compositional Features of the Extracts

将超临界CO2萃取技术应用于泥炭纤维素中有机脂类物质的提纯工作,并对萃取物进行色—质联用分析。结果表明,在萃取物中检出了一系列甲酯类、乙酯类、少量有机酸及正构烷烃组分。首次检出的脂肪酸乙酯系列化合物多数呈高碳数分布,具偶碳优势。长链正构烷烃主峰碳为nC33或nC31,具有明显的奇碳优势,这在一定程度上反映了泥炭生成过程的气候条件,记录了气候变化的信息。同时也显示出超临界CO2萃取技术能够很好地完成除去纤维素中有机脂类这一重要环节,有利于提高泥炭纤维素δ13C值检测的准确度,为超临界流体萃取技术在地学中的应用开辟了一个新途径。

Supercritical fluid extraction method （SFEm） has been used for the purification of peat cellulose and the extracts were analyzed and determined by gas chromatography-mass spectrometry. Series of methyl esters, ethyl esters and n-alkanes as well as small amount of fatty acids were detected. Cmax of long-chain n-alkanes , being typical of oddto-even carbon number predominance, are at C29, C31, C33. Most of the series of ethyl esters which have not been reported by far have characteristic of a distribution at high carbon number and distinct even-to-odd carbon number predominance. All of this, to a certain extent, discloses the information of climatic condition and variation in the process of the formation of peat. Supercritical fluid extraction method is indicated to be capable of removing lipids successfully from peat cellulose, which is in favor of improving the accuracy of δ^13C value in peat cellulose, and opens another new road for the application of SFEm in earth science.