Source Characterization of Polycyclic Aromatic Hydrocarbons by Using Their Molecular Indices: An Overview of Possibilities - Reviews of Environmental Contamination and Toxicology - page 103

5.6.3 Perylene

Perylene (PER) ratios are useful for discriminating between natural and coal-derived
PAHs. Low abundance of PER (<10% of TPAH, or of total five-ringed PAHs) may
indicate non-natural production (Calvacante et al. 2009 ; Gogou et al. 2000 ; Wang
et al. 2014 ). Conversely, high amounts of perylene (>10% of TPAH) indicate that
the PAHs have a natural origin, and when PER is >10% of the total five-ringed
PAHs, the main PER source is regarded to be diagenesis under reducing conditions
(Boll et al. 2008 ; Calvacante et al. 2009 ; Fan et al. 2011 ; Stout et al. 2001a ). The
relative abundance of PER over five-ringed PAHs (B[ b + k ]F + BaP + BeP + DA) has
been used to identify whether the PAH contamination in intertidal sediments in
Brazil was of natural or petrogenic origin (De Fatima et al. 2007 ), and to estimate
the contribution of fluvial PAHs to coastal sediments (Luo et al. 2008 ).
The PER/BeP (Gogou et al. 2000 ) and PER/BaP (Stout et al. 2001a ) ratios can
be used to identify that PAHs have a natural origin. The PER/PY0 ratio has been
used by Abrajano et al. ( 2003 ) to indicate diagenetic origin for retene. If such ratios
are high, the PER is from natural or petrogenic sources (e.g., coals). The PER/BaP
ratio is recalcitrant under aerobic and evaporative conditions in sediments (Uhler
and Emsbo-Mattingly 2006 ).

5.6.4 Ratio of Indeno[ 1 , 2 , 3 - cd ]pyrene to Benzo[ ghi ]perylene

The indeno[ 1 , 2 , 3 - cd ]pyrene/benzo[ ghi ]perylene (IP/ ghi ) ratio has been used by
several researchers to distinguish/apportion distinct pyrolytic sources (and, specifi-
cally, automobile sources) of contamination in sediments (Agarwal 2009 ; Larsen
and Baker 2003 ; Magi et al. 2002 ; Morillo et al. 2008b ; Park et al. 2002 ; Sicre et al.
1987 ; Van Drooge et al. 2012 ; Zhang et al. 2005 ). Examples include automobile
exhausts, gasoline emissions, coal-fired domestic heaters, biomass combustion and
other forms of combustion. Sometimes the IP/ghi ratio is studied in conjunction
with the dimethylphenanthrene ratio (DMP), the BaA/C0 or the FL0/PY0 ratios
(Dvorska et al. 2011 ; Walker and Dickhut 2001 ; Yunker et al. 2002 ).
In Fig. 20 , the IP/ ghi is greater than 0.25 for most pyrogenic sources except for
used lubricants and the combustion of gasoline, of jet fuel, and occasionally of diesel.
If such specific sources are absent, an IP/ ghi < 0.25 implies strong petroleum inputs
(Yunker et al. 2002 ). If 0.25 < IP/ ghi < 1, mixed sources are possible. Ratios >1 imply
combustion sources if certain petrogenics (e.g., asphalt, tire particles, coals) are
excluded. Wood and coal combustion may be discriminated by the IP/ ghi ratio, but
they sometimes yield IP/ ghi < 1 (Fig. 20 ; Guillon et al. 2013 ). Furthermore, patterns
for pyrogenic sources (e.g., automobile) are hardly distinguishable from each other
in Fig. 20 because IP/ ghi ratios for vehicle, diesel emissions and other pyrogenic
sources overlap. For this reason, PAH patterns from local sources should be scruti-
nized before the IP/ ghi is used as a pyrogenic indicator for atmospheric emissions.
It has been argued that there is uncertainty about the IP/ghi ratio, its threshold
values, and its correlation with other ratios (Yunker et al. 2002 ). Yan et al. ( 2006 )
reported that the IP/ ghi had little to no correlation with the ʴ 13 C Py or with the FL0/