Source Characterization of Polycyclic Aromatic Hydrocarbons by Using Their Molecular Indices: An Overview of Possibilities - Reviews of Environmental Contamination and Toxicology - page 110

Fig. 23 The LPAH / HPAH ratio for different sources. See Fig. 9 for the symbols and the text for
explanation

− 1

HPAH, then: Σ
Σ

COMB
PAH

LPAH
HPAH

. Accordingly, pyrolytic PAHs = ʣCOMB/

= + 1

ʣPAH, and ʣCOMB/ʣPAH <0.3 (or LPAH/HPAH ≥2.3) indicates petroleum. When
ʣCOMB/ʣPAH >0.7 (or LPAH/HPAH ≤0.4) a pyrolytic origin is likely (Hwang
et al. 2003 ; Tobiszewski and Namiesnik 2012 ). Phenanthrene and anthracene
(MW = 178) are not included in ʣCOMB because they may be of petrogenic origin,
whereas perylene usually originates from natural sources (Gogou et al. 2000 ).