Figure 5
From: Role of pyrite in formation of hydroxyl radicals in coal: possible implications for human health
OH generation comparison between the organic carbon and FeS2 fractions of coal, measured with APF. In both experiments, APF was exposed to 20 m2/L particle loadings with additions of either coal (NIST #1635, coal that does not produce detectable levels of •OH) or pyrite for 24 hrs in the dark followed by fluorescence measurements. In the top curve, pyrite was mixed with incremental additions of coal and in the bottom curve coal was mixed with incremental additions of pyrite. The last two points are repeat experiments. A typical error bar is included on one of the points to show that their standard deviations overlap. Fluorescent intensity has been converted to •OHAPF by a factor determined by reacting APF with known concentrations of H2O2 and HRP as in Figure 4.