title: Nitration of benzo[a]pyrene adsorbed on coal fly ash particles by nitrogen dioxide: role of thermal activation.
abstract: Nitration of benzo[a]pyrene (BaP) by nitrogen dioxide (NO2) adsorbed on the surface of thermally activated coal fly ash and model aluminosilicate particles led to the formation of nitrobenzo[a]pyrenes as verified by extraction and gas chromatography/mass spectrometry (GC/MS). In situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) was utilized to follow the nitration reaction on the surface of zeolite Y. Nitrobenzo[a]pyrene formation was observed along with the formation of nitrous acid and nitrate species. The formation of the BaP radical cation was also observed on thermally activated aluminosilicate particles by electron spin resonance (ESR) spectroscopy. On the basis of GC/MS, DRIFTS, and ESR spectroscopy results, a mechanism of nitration involving intermediate BaP radical cations generated on thermally activated aluminosilicate particles is proposed. These observations have led to the hypothesis that nitration of adsorbed polyaromatic hydrocarbons on coal fly ash by reaction with nitrogen oxides can occur in the smokestack, but with the aging of the fly ash particles, the extent of the nitration reaction will be diminished.
authors.affiliation: Department of Chemistry, The Ohio State University, 120 West 18th Avenue, Columbus, Ohio 43210, USA.
authors.forename: Robert L
authors.initials: RL
authors.lastname: Kristovich
authors.forename: Prabir K
authors.initials: PK
authors.lastname: Dutta
mesh_terms: D000327:Adsorption; D000393:Air Pollutants / Q000032:analysis*; D000538:Aluminum Silicates / Q000032:analysis; D001464:Barium / Q000032:analysis; D001564:Benzo(a)pyrene / Q000032:analysis*; D002244:Carbon / Q000032:analysis*; D002412:Cations; D002845:Chromatography; D003031:Coal; D060729:Coal Ash; D004578:Electron Spin Resonance Spectroscopy; D008401:Gas Chromatography-Mass Spectrometry; D006838:Hydrocarbons; D008956:Models, Chemical; D009584:Nitrogen / Q000032:analysis* / Q000737:chemistry; D009585:Nitrogen Dioxide / Q000032:analysis*; D009589:Nitrogen Oxides / Q000032:analysis; D052638:Particulate Matter; D010710:Phosphates / Q000032:analysis; D011084:Polycyclic Aromatic Hydrocarbons / Q000032:analysis*; D011083:Polycyclic Compounds / Q000032:analysis; D012964:Sodium / Q000032:analysis; D013052:Spectrometry, X-Ray Emission; D017550:Spectroscopy, Fourier Transform Infrared; D013997:Time Factors; D014961:X-Ray Diffraction; D015019:Yttrium / Q000032:analysis; D017641:Zeolites / Q000032:analysis*
chemical_list: D000393:Air Pollutants; D000538:Aluminum Silicates; D002412:Cations; D003031:Coal; D060729:Coal Ash; D006838:Hydrocarbons; D009589:Nitrogen Oxides; D052638:Particulate Matter; D010710:Phosphates; D011084:Polycyclic Aromatic Hydrocarbons; D011083:Polycyclic Compounds; D017641:Zeolites; C049037:aluminosilicate; D001464:Barium; D001564:Benzo(a)pyrene; D015019:Yttrium; D002244:Carbon; D012964:Sodium; D009584:Nitrogen; D009585:Nitrogen Dioxide