Model studies of photochemical oxidation of carcinogenic polyaromatic hydrocarbons

Paalme, Lia; Irha, Natalya; Urbas, E.; Tsyban, A.V.; Кирсо, У.

doi:10.1016/0304-4203(90)90064-j

Cited by 9 publications

(4 citation statements)

References 0 publications

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“…Other PAHs produce the same classes of compounds; however, their particular products may differ. Thus, tetracarboxylic anhydride is formed from linear anthracene, but the bent phenanthrene does not form this product type (44). The greater stability of the phenanthrene structure observed in this work in comparison to anthracene is consistent with literature results (45,46).…”

Section: Polyaromatic Hydrocarbonssupporting

confidence: 92%

“…The total amounts of CO 2 , normalized to the naturally present internal standard argon were estimated to be 10, 4, 3 and 1 for BaP, anthracene, naphthalene and phenanthrene, respectively. This same sequence of activity has been described in the literature (43,44), where oxidation of PAHs was conducted catalytically in the gas phase and photochemically on alumina or silica support. BRUCKNER and BAERNS (43) showed that PAHs have much higher chemical activities when supported than when in water solutions.…”

Section: Polyaromatic Hydrocarbonsmentioning

confidence: 82%

“…BRUCKNER and BAERNS (43) showed that PAHs have much higher chemical activities when supported than when in water solutions. PAALME et al (44) pointed out the similarity of the reaction pathways for different PAHs, an indication that the products of inner-and outer-ring oxidation are formed in primary steps while their decomposition occurs consecutively. These steps could be indicated by the exothermic peaks in Figure 16 for BaP and anthracene.…”

Section: Polyaromatic Hydrocarbonsmentioning

confidence: 99%

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Studies of the Formation of Smoke Phenols

D'yakonov¹,

Walker²,

Brown³

et al. 2008

Beiträge Zur Tabakforschung International/Contributions to Tobacco Research

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Processes involving or forming phenols during combustion of tobacco were studied by differential scanning calorimetry (DSC), thermogravimetry (TG), mass-spectrometry (MS), X-band electron spin resonance (ESR), and thermocouple (TCT) and infrared thermography (IRT) methods. Thermochemical properties of polyhydroxybenzenes, polynuclear aromatic hydrocarbons (PAHs), and carbohydrates were investigated both individually and when the compounds were embedded in combustible or non-combustible matrices; the compounds were studied in an O2/He atmosphere at temperatures up to 800 °C, with a heating rate up to 60 °C/min. ESR of the mainstream smoke ‘tar’ was performed at temperatures down to -253 °C. The radicals found differed in their magnetic behavior depending on the material studied; this difference was attributed to the presence of relatively unstable isolated semiquinone and/or PAH-type molecules and the more stable quinone-hydroquinone-semiquinone redox complex.Phenols themselves were found to affect combustion by radical scavenging and initiation. Added carbohydrates introduced diffusion limitations to oxygen. They also affected the combustion temperatures and could intensify the formation of phenols via quinone. Oxidation of PAHs was investigated and enthalpies were determined. These enthalpies decreased from benzo[a]pyrene (BaP) to anthracene, naphthalene and phenanthrene.

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Section: Polyaromatic Hydrocarbonssupporting

confidence: 92%

Section: Polyaromatic Hydrocarbonsmentioning

confidence: 82%

Section: Polyaromatic Hydrocarbonsmentioning

confidence: 99%

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Studies of the Formation of Smoke Phenols

D'yakonov¹,

Walker²,

Brown³

et al. 2008

Beiträge Zur Tabakforschung International/Contributions to Tobacco Research

View full text Add to dashboard Cite

show abstract

“…Polycyclic aromatic hydrocarbons are also present in crude oil and its products [7][8][9]11], thus their thoughtless or accidental discharge can seriously pollute the environment. These compounds are poorly soluble in water [25] and slowly degradable in natural conditions [20,26,27]. They are, however, readily adsorbed onto particles present in natural waters, which are then deposited on the bottom, where they are buried [20,23].…”

Section: Introductionmentioning

confidence: 99%