Polycyclic aromatic hydrocarbons of coal fly ash: analysis by gas-liquid chromatography using nematic liquid crystals.

The seasonal variations over a period of 12 m in the amounts of polycyclic aromatic hydrocarbons (PAH) in fly-ash samples collected from the electrostatic precipitator of a thermal power plant have been studied. PAH generally did not show much seasonal variation. The gas-liquid chromatographic (GLC) analysis of benzene extract of fly ash showed the presence of 28 polyaromatic hydrocarbons, of which only phenanthrene, anthracene, pyrene, benz[a]anthracene, chrysene, and benzo[a]pyrene could be identified.