Contribution of nitropyrene to the mutagenic activity of coal fly ash

Stack‐collected coal fly ash from western low‐sulfur coal was extracted with 60:40 benzene/methanol. This extract was fractionated by preparative‐scale high performance liquid chromatography (HPLC) and the mutagenic activity of 14 fractions was evaluated by microbial assay with Salmonella typhimurium TA1538. A widespread distribution of direct‐acting mutagens, which probably includes both mono‐ and dinitroaromatics, was detected. HPLC methods were also used to isolate 1‐nitropyrene from the total benzene/methanol extract. The identification of 1‐nitropyrene was based on gas chromatographic and HPLC retention measurements and mass spectral data. The concentration of 1‐nitropyrene in the ash extract was determined by quantitative HPLC analyses. Mutagenicity assays of the total extract and an authentic 1‐nitropyrene standard with Salmonella strains TA1538, TA100, and TA98 indicated that the 1‐nitropyrene accounts for approximately 0.03‐0.16% of the total mutagenic activity of the extract.