An environmental research on trace elements in freshwater fish by neutron activation analysis.

For a case study of environmental contamination, radiochemical activation analysis has been applied to the crucians collected in the Han River. Sixteen trace elements (Hg, Cd, As, Br, Cu, Na, K, Se, Cr, Hf, Rb, Fe, Zn, Co, La, and Cs) were separated into three groups using distillation and diethyldithiocarbamate extraction methods, and their contents were determined by a single comparator method. Compared with the values 15 years ago, the values for mercury and cadmium have been drastically decreased at the middle and lower part of the river, but no typical change is found in other elements.