Analysis and Characterization of Chemically Modified Coal Macerals Using Density Gradient Centrifugation

摘要

Changes brought about in coal macerals by mild, non-destructive reactions such as -0- alkylation can be monitored by using density gradient centrifugation. Large changes in maceral group densities have been observed when active hydroxyl groups of the original coal sample are alkylated with methyl or butyl groups. All three maceral groups exhibit a shift to lower densities. When single, pre-separated density fractions are alkylated and then examined by density gradient techniques, inertinite and exinite macerals show new multiple density bands developing. This suggests that different chemical domains or different macerals can be isolated from individual maceral groups. 6 refs., 4 figs. (ERA citation 10:043649)