State Key Laboratory of Environmental Geochemistry;
Institute of Geochemistry;
Chinese Academy of Sciences;
Guiyang 550002;
Guizhou;
China;
University of Chinese Academy of Sciences;
Beijing 100049;
China;
State Key Laboratory of Organic Geochemistry;
Guangzhou Institute of Geochemistry;
Chinese Academy of Sciences;
Guangzhou 510640;
China;