pubmed-article:12398324 | pubmed:abstractText | The contents of arsenic and selenium in 33 coals collected from the main coal mines in northeastern, northern and eastern China were determined by flow injection-hydride generation and non-dispersion atomic fluorescence spectrometry (HGAFS). The concentrations of As in the northeast region are relatively higher with the values > 100 microg g(-1); in the east they are lower with values < 100 microg g(-1). The contents of Se in these three areas are the opposite, most of them from the northeast mines are < 1 microg g(-1) and increase as the mine location advances south where the average contents are > 5 microg g(-1). | lld:pubmed |