Thermodynamic behavior of stable carbon isotopic compositions of individual polycyclic aromatic hydrocarbons derived from automobiles

Tomoaki Okuda, Hideshige Takada, Hiroshi Naraoka

Research output: Contribution to journalArticle

19 Citations (Scopus)

Abstract

Concentrations, molecular compositions, and compound-specific stable carbon isotopic compositions (δ13C) of polycyclic aromatic hydrocarbons (PAHs) in gasoline exhaust particles (GEPs) and diesel exhaust particles (DEPs) were investigated in this study. δ13C of PAHs in GEPs ranged from -13.3‰ to -26.8‰, and that in DEPs ranged from -21.7‰ to -26.3‰. The interspecies δ13C variations in each sample were 5.3 ± 2.2‰ in GEPs and 2.6 ± 1.3‰ in DEPs. PAHs in GEPs show larger interspecies δ13C variation than those in DEPs; hence, a degree of carbon isotopic fractionation during the conversion from fuel to PAH seems to be larger in gasoline engines than that in diesel engines. Pyrene series PAHs, which consist of only hexagonal rings, in almost all GEP samples show strong negative correlation between the H/C ratio and δ13C whereas fluoranthene series PAHs, which contain a pentagonal ring, show less systematic isotopic behavior in GEP samples. A kinetic isotope effect in thermal cracking of organic macromolecules may be minor for PAH formation in vehicle engines. We suggest that the isotopic trend of pyrene series in GEPs can be explained by a thermodynamic isotope effect, and that disturbance from isotopic equilibrium may cause a weak correlation between the isotopic behavior and the H/C ratio among the interspecies PAHs.

Original languageEnglish
Pages (from-to)219-236
Number of pages18
JournalPolycyclic Aromatic Compounds
Volume23
Issue number2
DOIs
Publication statusPublished - Jun 24 2003
Externally publishedYes

Fingerprint

Polycyclic Aromatic Hydrocarbons
Polycyclic aromatic hydrocarbons
Automobiles
Gasoline
Carbon
Thermodynamics
Vehicle Emissions
Chemical analysis
Pyrene
Isotopes
Engines
Fractionation
Macromolecules
Diesel engines
Kinetics

All Science Journal Classification (ASJC) codes

  • Organic Chemistry

Cite this

Thermodynamic behavior of stable carbon isotopic compositions of individual polycyclic aromatic hydrocarbons derived from automobiles. / Okuda, Tomoaki; Takada, Hideshige; Naraoka, Hiroshi.

In: Polycyclic Aromatic Compounds, Vol. 23, No. 2, 24.06.2003, p. 219-236.

Research output: Contribution to journalArticle

@article{2c20fdc0b40d4a2aa72390e58a6f7af3,
title = "Thermodynamic behavior of stable carbon isotopic compositions of individual polycyclic aromatic hydrocarbons derived from automobiles",
abstract = "Concentrations, molecular compositions, and compound-specific stable carbon isotopic compositions (δ13C) of polycyclic aromatic hydrocarbons (PAHs) in gasoline exhaust particles (GEPs) and diesel exhaust particles (DEPs) were investigated in this study. δ13C of PAHs in GEPs ranged from -13.3‰ to -26.8‰, and that in DEPs ranged from -21.7‰ to -26.3‰. The interspecies δ13C variations in each sample were 5.3 ± 2.2‰ in GEPs and 2.6 ± 1.3‰ in DEPs. PAHs in GEPs show larger interspecies δ13C variation than those in DEPs; hence, a degree of carbon isotopic fractionation during the conversion from fuel to PAH seems to be larger in gasoline engines than that in diesel engines. Pyrene series PAHs, which consist of only hexagonal rings, in almost all GEP samples show strong negative correlation between the H/C ratio and δ13C whereas fluoranthene series PAHs, which contain a pentagonal ring, show less systematic isotopic behavior in GEP samples. A kinetic isotope effect in thermal cracking of organic macromolecules may be minor for PAH formation in vehicle engines. We suggest that the isotopic trend of pyrene series in GEPs can be explained by a thermodynamic isotope effect, and that disturbance from isotopic equilibrium may cause a weak correlation between the isotopic behavior and the H/C ratio among the interspecies PAHs.",
author = "Tomoaki Okuda and Hideshige Takada and Hiroshi Naraoka",
year = "2003",
month = "6",
day = "24",
doi = "10.1080/10406630308060",
language = "English",
volume = "23",
pages = "219--236",
journal = "Polycyclic Aromatic Compounds",
issn = "1040-6638",
publisher = "Taylor and Francis Ltd.",
number = "2",

}

TY - JOUR

T1 - Thermodynamic behavior of stable carbon isotopic compositions of individual polycyclic aromatic hydrocarbons derived from automobiles

AU - Okuda, Tomoaki

AU - Takada, Hideshige

AU - Naraoka, Hiroshi

PY - 2003/6/24

Y1 - 2003/6/24

N2 - Concentrations, molecular compositions, and compound-specific stable carbon isotopic compositions (δ13C) of polycyclic aromatic hydrocarbons (PAHs) in gasoline exhaust particles (GEPs) and diesel exhaust particles (DEPs) were investigated in this study. δ13C of PAHs in GEPs ranged from -13.3‰ to -26.8‰, and that in DEPs ranged from -21.7‰ to -26.3‰. The interspecies δ13C variations in each sample were 5.3 ± 2.2‰ in GEPs and 2.6 ± 1.3‰ in DEPs. PAHs in GEPs show larger interspecies δ13C variation than those in DEPs; hence, a degree of carbon isotopic fractionation during the conversion from fuel to PAH seems to be larger in gasoline engines than that in diesel engines. Pyrene series PAHs, which consist of only hexagonal rings, in almost all GEP samples show strong negative correlation between the H/C ratio and δ13C whereas fluoranthene series PAHs, which contain a pentagonal ring, show less systematic isotopic behavior in GEP samples. A kinetic isotope effect in thermal cracking of organic macromolecules may be minor for PAH formation in vehicle engines. We suggest that the isotopic trend of pyrene series in GEPs can be explained by a thermodynamic isotope effect, and that disturbance from isotopic equilibrium may cause a weak correlation between the isotopic behavior and the H/C ratio among the interspecies PAHs.

AB - Concentrations, molecular compositions, and compound-specific stable carbon isotopic compositions (δ13C) of polycyclic aromatic hydrocarbons (PAHs) in gasoline exhaust particles (GEPs) and diesel exhaust particles (DEPs) were investigated in this study. δ13C of PAHs in GEPs ranged from -13.3‰ to -26.8‰, and that in DEPs ranged from -21.7‰ to -26.3‰. The interspecies δ13C variations in each sample were 5.3 ± 2.2‰ in GEPs and 2.6 ± 1.3‰ in DEPs. PAHs in GEPs show larger interspecies δ13C variation than those in DEPs; hence, a degree of carbon isotopic fractionation during the conversion from fuel to PAH seems to be larger in gasoline engines than that in diesel engines. Pyrene series PAHs, which consist of only hexagonal rings, in almost all GEP samples show strong negative correlation between the H/C ratio and δ13C whereas fluoranthene series PAHs, which contain a pentagonal ring, show less systematic isotopic behavior in GEP samples. A kinetic isotope effect in thermal cracking of organic macromolecules may be minor for PAH formation in vehicle engines. We suggest that the isotopic trend of pyrene series in GEPs can be explained by a thermodynamic isotope effect, and that disturbance from isotopic equilibrium may cause a weak correlation between the isotopic behavior and the H/C ratio among the interspecies PAHs.

UR - http://www.scopus.com/inward/record.url?scp=0038721056&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0038721056&partnerID=8YFLogxK

U2 - 10.1080/10406630308060

DO - 10.1080/10406630308060

M3 - Article

VL - 23

SP - 219

EP - 236

JO - Polycyclic Aromatic Compounds

JF - Polycyclic Aromatic Compounds

SN - 1040-6638

IS - 2

ER -