Extraction and identification of elemental carbon in sediment and its environmental and climatic implications

Abstract

Elemental carbon was extracted from sediments by chemical oxidation and identified by Raman spectroscopy. The experimental results indicate that elemental carbon, defined by processing, is a continuum ranging from single crystal graphite to amorphous carbon. Chemical oxidation is a feasible method to extract elemental carbon from sediments, and when experimental condition and time are properly controlled, it can remove organic carbon without any loss of elemental carbon. However, due to the differences in experimental conditions and methods, different results have been obtained. Therefore, we believe that the determination of standard sample and its concentration as well as the unification of the experimental method are of great importance. Also, the unification and definition of all these carbon particulates can facilitate transect comparison and further research in related fields. In profile research, elemental carbon was extracted and determined by using the same method. The elemental carbon curve tends to change with other climatic proxies, indicating elemental carbon can provide another new proxy for climatic and environmental changes. Based on the analysis, we deduce that the elemental carbon record has different implications for climate and environmental changes on different timescales.

Keywords

elemental carbon / chemical oxidation / Raman spectroscopy / graphite / paleoclimatic and environmental proxy