Fluorescence spectrum characteristics of dissolved organic matter and its effect on occurrence of trace elements in coal

Trace elements in coal exist in many forms,most of which are combined with organic matter. Coal organic matter content also determines the degree of integration and the bound state of trace elements in coal. In terms of lig- nite,bituminous and anthracite coal,this paper analyzed the trace element content monitored by ICP-MS,studied the fluorescence spectroscopy characteristics of the dissolved organic matter (DOM) existed in coal using 3D-EEM Absor- bance and Fluorescence Scanning Spectrometer,and conducted a further investigation on the relationships of DOM with the degree of coalification,the levels and status of trace elements in coal with a utility of PARAFAC system. The con- clusions indicated that there was significant difference in trace elements. The highest content was ranked by As,Mg,Cd and Mn in lignite,while Li and Sr in anthracite. There was no significant difference in the content of Cu and Co. The fluorescence spectrum characteristics of dissolved organic matter revealed that only humic-acid fluorescence peak was detected in lignite and both the peaks of humic acid and protein in bituminous,while no fluorescence peak in anthracite. Also the fluorescence intensity decreased with the increase of coal rank. It was found that the occurrence of cer- tain trace elements related with the dissolved organic matter in coal,which the higher fluorescence intensity of humic acid,the richer the contents of trace elements for As and Mg,while the rarer for Li and Sr.