Ambient air - Report on nitro- and oxy-PAHs - Origin, toxicity, concentrations and measurement methods

This Technical Report is focused on the presence of nitro- and oxy-PAH compounds in ambient air. It describes how nitro- and oxy-PAH are formed, what typical concentrations are found, what is known about their toxicity, and what sampling and measurement techniques are available. The conclusions of this report are that nitro- and oxy-PAH concentrations are present in the atmosphere in level that are of concern regarding their high toxicity. Information on the presence of these compounds in ambient air is at least as relevant as information about PAH. Validated techniques for the measurement of nitro- and oxy-PAH are available.

Außenluft - Bericht über Nitro- und Oxy-PAHs - Herkunft, Toxizität, Konzentrationen und Messverfahren

Air ambiant - Rapport sur les nitro- et oxy-HAP - Origine, toxicité, concentrations et méthodes de mesure

Zunanji zrak - Poročilo za nitro- in oksi-PAH - Izvor, strupenost, koncentracije in merilne metode

To tehnično poročilo se osredotoča na prisotnost nitro- in oksi-PAH spojin v zunanjem zraku. Opisuje, kako nastanejo nitro- and oksi-PAH spojine, kakšne so tipične koncentracije, kaj je znano o njihovi toksičnosti in katere tehnike vzorčenja in meritev so na voljo. Ugotovitve tega poročila kažejo, da je raven koncentracije nitro- in oksi-PAH spojin v ozračju zaskrbljujoča z vidika njihove močne toksičnosti. Informacije o prisotnosti teh spojin v zunanjem zraku so najmanj tako pomembne kot informacije o PAH-u. Potrjene merilne metode za merjenje nitro- in oksi-PAH spojin so na voljo.

General Information

Status
Published
Publication Date
29-Nov-2016
Current Stage
6060 - Definitive text made available (DAV) - Publishing
Due Date
30-Nov-2016
Completion Date
30-Nov-2016

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SLOVENSKI STANDARD
SIST-TP CEN/TR 16998:2017
01-julij-2017

=XQDQML]UDN3RURþLOR]DQLWURLQRNVL3$+,]YRUVWUXSHQRVWNRQFHQWUDFLMHLQ

PHULOQHPHWRGH
Ambient air - Report on nitro- and oxy-PAH - Origin, toxicity concentrations and
measurement methods
Außenluft - Nitro- und Oxy-PAHs - Herkunft, Toxizität, Konzentrationen und
Messverfahren

Air ambiant - Rapport concernant les HAP nitrés et les HAP oxygénés - Origine, toxicité,

concentrations et méthodes de mesure
Ta slovenski standard je istoveten z: CEN/TR 16998:2016
ICS:
13.040.20 Kakovost okoljskega zraka Ambient atmospheres
SIST-TP CEN/TR 16998:2017 en,fr,de

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST-TP CEN/TR 16998:2017
CEN/TR 16998
TECHNICAL REPORT
RAPPORT TECHNIQUE
November 2016
TECHNISCHER BERICHT
ICS 13.040.20
English Version
Ambient air - Report on nitro- and oxy-PAHs - Origin,
toxicity, concentrations and measurement methods

Air ambiant - Rapport sur les nitro- et oxy-HAP - Außenluft - Bericht über Nitro- und Oxy-PAHs -

Origine, toxicité, concentrations et méthodes de Herkunft, Toxizität, Konzentrationen und

mesure Messverfahren

This Technical Report was approved by CEN on 21 October 2016. It has been drawn up by the Technical Committee CEN/TC 264.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,

Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,

Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and

United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels

© 2016 CEN All rights of exploitation in any form and by any means reserved Ref. No. CEN/TR 16998:2016 E

worldwide for CEN national Members.
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Contents Page

European foreword ....................................................................................................................................................... 3

Introduction .................................................................................................................................................................... 4

1 Scope .................................................................................................................................................................... 5

2 Symbols and abbreviations ......................................................................................................................... 5

3 Literature overview ....................................................................................................................................... 5

4 Conclusions .................................................................................................................................................... 20

5 Recommendations ....................................................................................................................................... 20

Annex A (informative) Sampling and analysis by GC-MS of some nitro- and oxy-PAHs

associated to ambient particulate matter ........................................................................................... 22

A.1 Sampling .......................................................................................................................................................... 22

A.2 Analytical materials .................................................................................................................................... 22

A.2.1 Glassware and sample handling ............................................................................................................. 22

A.2.2 Reagents and Solvents ................................................................................................................................ 22

A.2.3 Extraction apparatus and materials ...................................................................................................... 23

A.2.4 Evaporation apparatus and materials .................................................................................................. 24

A.2.5 Clean-up Material ......................................................................................................................................... 24

A.2.6 Weighting Apparatus .................................................................................................................................. 24

A.2.7 Analytical system ......................................................................................................................................... 24

A.3 Extraction ........................................................................................................................................................ 24

A.4 Clean-up ........................................................................................................................................................... 24

A.5 Analysis ............................................................................................................................................................ 25

A.6 Results .............................................................................................................................................................. 25

A.7 Quality assurance ......................................................................................................................................... 30

Annex B (informative) Carcinogenicity and references to nitro- and oxy-PAHs ................................ 31

Annex C (informative) Mutagenicity of nitro-PAHs ...................................................................................... 34

Annex D (informative) Diesel exhaust data ..................................................................................................... 35

Annex E (informative) Structures of nitro- and oxy-PAHs referred in this Technical Report ...... 36

Bibliography ................................................................................................................................................................. 43

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European foreword

This document (CEN/TR 16998:2016) has been prepared by Technical Committee CEN/TC 264 “Air

quality”, the secretariat of which is held by DIN.

Attention is drawn to the possibility that some of the elements of this document may be the subject of

patent rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent

rights.
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Introduction

Nitro-PAHs and oxy-PAHs are found in ambient air samples and there are strong indications that they

are as harmful as PAHS. Several compounds are classified as probably carcinogenic for humans (see

Table in Annex A) and nitro-PAHs are reported to be strongly mutagenic. Photooxidation of volatile

PAHs gives rise to the formation of secondary aerosols (Chan et al. 2009, Kautzman et al. 2010, Shakya

and Griffin, 2010).

1-Nitropyrene and 2-nitrofluorene are discussed as marker compounds for diesel exhaust and other

combustion processes. 2-Nitropyrene and 2-nitrofluoranthene are good marker substances for the

formation of nitro-PAHs by secondary reactions.

This Technical Report presents the state of the art of the oxy- and nitro-PAHS topics.

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1 Scope

This Technical Report is focused on the presence of nitro- and oxy-PAHs in ambient air. It describes

how nitro- and oxy-PAH are formed, what typical concentrations are found, what is known about their

toxicity, and what sampling and measurement techniques are available.

The conclusions of this report are that nitro- and oxy-PAHs concentrations are present in the

atmosphere in levels that are of concern regarding their high toxicity. Information on the presence of

these compounds in ambient air is as relevant as information about PAHs. Validated techniques for the

measurement of nitro- and oxy-PAHs are available.
2 Symbols and abbreviations
DNA Deoxyribonucleic acid
EI Electron ionization
CD Chemiluminescence detection
FD Fluorescence detection
GC-MS Gas chromatography – mass spectrometry

GC-NICI-MS Gas chromatography – negative ion chemical ionization – mass spectrometry

HPLC High performance liquid chromatography
HPLC-FD HPLC – fluorescence detection
HPLC-CD HPLC – chemiluminescence detection
IARC International Agency for Research on Cancer
LC Liquid chromatography
MS Mass spectrometry
NICI Negative ion chemical ionization
Nitro-PAHs Nitrated polycyclic aromatic hydrocarbons
Oxy-PAHs Oxygenated polycyclic aromatic hydrocarbons
PAHs Polycyclic aromatic hydrocarbons
SPE Solid phase extraction
ToF-MS Time of flight mass spectrometry
3 Literature overview
3.1 Nitro-PAHs
3.1.1 Sources
3.1.1.1 General

Nitro-PAHs in the atmosphere originate mainly from combustion sources and are produced from both

gas and heterogeneous phase reactions of the parent PAHs with atmospheric oxidants such as NO ,

N O , O , OH and peroxide radicals (Arey et al., 1986; Atkinson et al., 1990; Keyte et al., 2013; Pitts et al.,

2 5 3
1985; Pitts Jr et al., 1978) in the presence of nitrogen oxides.
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3.1.1.2 Direct emissions

Nitro-PAHs from direct emissions are formed by high temperature electrophilic nitration of PAHs with

NO during combustion processes (Nielsen, 1984). Nitro-PAHs have been observed in vehicle exhaust

(particularly diesel), industrial emissions, waste incinerator emissions (DeMarini et al., 1996) and

emissions from domestic residential heating/cooking (Kinouchi et al., 1988; Van Houdt, 1990). Nitro-

PAHs are also emitted by wood burning but in relative low amounts due to low emissions of NO during

this type of combustion process (Alfheim and Ramdahl, 1984, Orasche et al., 2012; Orasche et al., 2013;

Shen et al., 2011; Shen et al., 2012a; Shen et al., 2012b), (Environmental Health Criteria (EHC) 229,

2003 and references therein).

Recently, nitro-PAHs have also been quantified in exhausts of modern biodiesel engines (Karavalakis et

al., 2010a; Karavalakis et al., 2010b; Karavalakis et al., 2011). Additionally, several studies have shown

the formation nitro-PAHs in situ on catalytic diesel particulate filters as they act as chemical reactors for

the nitration of PAHs (Carrara et al., 2010; Carrara and Niessner, 2011; Heeb et al., 2008). In this case,

nitro-PAHs would be considered as primarily emitted. Gasoline emissions have also been reported but

at lower concentration levels (Alsberg et al., 1985; Hayakawa et al., 1994; IARC, 1989; Sera et al., 1994).

Overall, 1-nitropyrene, 2-nitrofluorene and 2-nitrofluoranthene are the most abundant nitro-PAHs in

diesel and gasoline exhaust (gas and particulate phases) (Beije and Möller, 1988; Environmental Health

Criteria (EHC) 229, 2003; Finlayson-Pitts and Pitts Jr, 2000; Paputa-Peck et al., 1983; Schuetzle and

Perez, 1983).
3.1.1.3 Atmospheric formation

Gas-phase reactions of parent PAHs are initiated by OH radicals during the day and by NO radicals at

night in the presence of NO producing nitro-PAHs, with subsequent partitioning to or depositing on the

particulate matter. (Arey et al., 1986; Atkinson et al., 1989a; Atkinson et al., 1989b; Atkinson et al.,

1990; Atkinson and Arey, 1994; Environmental Health Criteria (EHC) 229, 2003; Helmig and Harger,

1994; Keyte et al., 2013; Sasaki et al., 1997; Vione et al., 2006).

Recently, research studies reported that heterogeneous reactions may be the dominant process for loss

of atmospheric PAHs and a significant source for nitro-PAHs in the atmosphere (Keyte et al., 2013;

Kwamena et al., 2007; Perraudin et al., 2007; Pöschl et al., 2001). These reactions may dramatically

differ from the homogeneous reactions in their rates, mechanisms, and products. Numerous studies

showed results obtained with model particles (soot, sea salt, organic aerosol, silica, graphite or azelaic

acid particles) coated artificially with single or a mixture of PAHs and their reaction with various

oxidants as OH, NO , O or NO (Cazaunau et al., 2010; Esteve et al., 2003; Kwamena et al., 2007; Miet et

3 3 2
al., 2009; Perraudin et al., 2005; Zhang et al., 2011).

Few studies reported results obtained with natural soot particles laboratory generated (liquid

carburant burners) (Bedjanian et al., 2010; Kwamena and Abbatt, 2008), with natural ambient air

particles (Ringuet et al., 2012b; Zimmermann et al., 2013) or with diesel engine exhaust particles

(Esteve et al., 2006; Kamens et al., 1990; Nguyen et al., 2009; Rattanavaraha et al., 2011).

Mechanistic reaction schemes for gas phase formation of nitro-derivatives of fluoranthene and

heterogeneous formation of isomeric nitro-benzo[a]pyrenes are shown in Figure 1 and 2, respectively.

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Figure 1 — Oxidation mechanisms of fluoranthene by OH during the day (Arey, 1998) and by NO

during the night (Atkinson and Arey, 1997)

Figure 2 — Mechanism proposed for the nitration of benzo[a]pyrene (Cazaunau et al., 2010)

22-Nitrofluoranthene and 2-nitropyrene are the most abundant substances formed by gas phase

reaction of PAHs with oxidants and oxides of nitrogen. A high 2-nitrofluoranthene/1-nitropyrene ratio

is a good indicator for the secondary formation of nitro-PAHs (Albinet et al., 2007b; Albinet et al., 2008;

Arey et al., 1989; Atkinson and Arey, 1994; Bamford and Baker, 2003; Reisen and Arey, 2005; Mariano

et al., 2000; Ringuet et al., 2012a; Ringuet et al., 2012c; Zielinska et al., 1989; Zimmermann et al., 2012).

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3.1.2 Concentrations, gas/particle partitioning and size distribution

Overall, in continental areas (urban, sub-urban and rural areas), nitro-PAHs atmospheric

concentrations are one or two orders lower than PAHs atmospheric concentrations. Nitro-PAHs

concentrations are in the range of 0,1 to 1000 pg·m in both, gaseous and particulate phases (e.g.

Albinet et al., 2007; Albinet et al., 2008a; Bamford and Baker, 2003; Ciccioli et al., 1995; Ciccioli et al.,

1996; Feilberg et al., 2001; Feilberg and Nielsen, 2001; Hayakawa et al., 1995a; Hayakawa et al., 2002;

Maria del Rosario Sienra, 2006; Valle-Hernandez et al., 2010; Wang et al., 2011). Nitronaphthalene

isomers in gas phase and 2-nitrofluoranthene and 9-nitroanthracene in particulate phase are generally

the most abundant nitro-PAHs and account for about 15 % to 50 % of the total nitro-PAHs

concentrations.
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Table 1 summarizes the reported concentration ranges of the most important nitro-PAHs.

Table 1 — List of concentration ranges of important nitro-PAHs in ambient air
Substance Concentration range ng/m
Traffic Urban Rural/remote
1-Nitronaphthalene 0,07 – 0,2 (n, o) 0,2 (h, n) 0,01 – 0,2 (h, n)
2-Nitronaphthalene 0,03 – 0,06 (n, o) 0,12 (h, n) 0,01 – 0,1 (h, n)

2-Nitrofluorene 0,001 – 0,021 (l, n) 0,05 – 0,4 (d, g, h, n) 0,001 – 0,005 (h, n)

9-Nitroanthracene 0,002 – 0,01 (n, o) 0,03 – 0,2 (a, c, d, g, h, j, l, n) 0,002 – 0,03 (g, h, n)

3-Nitrophenanthrene 0,007 – 0,1 (n, o) 0,001 – 0,02 (l, o) 0,0007 – 0,001 (o)

9-Nitrophenanthrene 0,005 – 0,05 (l, n) 0,01 – 0,3 (h, i, n) 0,0002 – 0,03 (h, n)

2-Nitrofluoranthene 0,03 – 0,2 (l, o) 0,03 – 2 (a, e, f, g, j, l, m, n) 0,02 – 0,03 (e, k, n)

3-Nitrofluoranthene 0,018 (i) 0,003 – 0,1 (d, j, l) 0,01 (e)

1-Nitropyrene 0,02 – 0,2 (l, o) 0,01 – 2 (a, b, e, f, g, h, j, l, n) 0,0006 – 0,01 (e, h, n, o)

2-Nitropyrene 0,007 – 0,2 (n, o) 0,01 – 0,04 (a, h, j, n) 0,001 – 0,08 (e, h, k, n)

4-Nitropyrene 0,02 – 0,03 (o) 0,001 (h, n) 0,0006 (h, n)
1,3-Dinitropyrene 0,0009 – 0,02 (n, o) 0,01 – 0,03 (d, h, n) 0,004 (n)
1,6-Dinitropyrene up to 0,0002 (o) 0,01 (d, h, n) 0,0001 – 0,004 (n)

7-Nitrobenzo[a]anthracene 0,005 – 0,01 (n, o) 0,004 – 0,3 (a, h, l, m) 0,002 (h, n)

6-Nitrochrysene 0,003 – 0,004 (n, o) up to 1,5 (b, h, j, l, n) 0,0003 – 0,002 (e, h, n)

6-Nitrobenzo[a]pyrene 0,007 – 0,01 (l, n) 0,001 – 0,01 (h, n) 0,0002 – 0,005 (n, o)

3-Nitrobenzanthrone 0,001 – 0,01 (l) – –
a) Atkinson et al. (1988) Glendora (USA)
b) Matsushita and Ida (1986) Tokio (Japan)
c) Hunt and Meisel (1995) Fresno (USA)
d) Tokiwa et al. (1990a) Sapporo (Japan)
e) Vasconcellos et al. (1998) Alta Floresta (Brazil)
f) Wilson et al. (1995) Houston (USA)
g) Berlincioni et al. (1995) Florence (Italy)
h) Albinet et al. (2007) Marseille (France)
i) Mücke et al. (2009) Munich (Germany)
j) Di Filippo et al. (2010) Rome (Italy)
k) Tsapakis et al. (2007) Finokalia (Greece)
l) Valle-Hernandez et al. (2010) Mexico City (Mexico)
m) Wang et al. (2011) Bejing (China)
n) Albinet et al. (2008a, 2008b) Chamonix, Maurienne (France)
o) Ringuet et al. (2012) Paris (France)
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Nitro-PAHs gas/particle partitioning is poorly documented (Albinet et al., 2007; Albinet et al., 2008a;

Araki et al., 2009; Atkinson and Arey, 1994; Bamford and Baker, 2003; Dimashki et al., 2000; Huang et

al., 2014; Reisen and Arey, 2005; Wilson et al., 1995). 2-Rings nitro-PAHs (nitronaphthalenes) are

mainly associated to the gaseous phase. Nitro-PAHs with 4 or more rings are mainly bound to particles.

3-ring nitro-PAHs are partitioned in both gaseous and particulate phase. Due to their relative low

vapour pressures (<10 Pa at 20 °C, Yaffe et al., 2001), nitro-PAHs resulting from gas phase reactions

condense immediately to ambient particles (Fan et al., 1995). Gas/particle partition is depending on

their vapour pressure and the ambient conditions as temperature but also on their origin (primary or

secondary) (Albinet et al., 2007; Albinet et al., 2008a; Wilson et al., 1995).

Very few papers showed results about the particle size distribution of nitro-PAHs in ambient air

(Albinet et al., 2008b; Cecinato et al., 1999; Di Filippo et al., 2010; Hayakawa et al., 1995a; Hayakawa et

al., 1995b; Jinhui and Lee, 2000; Kawanaka et al., 2004; Kawanaka et al., 2008; Ringuet et al., 2012a;

Teixeira et al., 2011). Overall, nitro-PAHs are mainly associated (>90 %) to the fine particle fraction

(D < 1 µm) and about 20 % are associated to the ultrafine particle fraction (D < 0,1 µm). These results

p p

are important information regarding the risk assessment because nitro-PAHs can thus penetrate deeply

into the lung.

Nitro-PAHs react with hydroxide and nitrate radicals, with ozone and they are decomposed by

photolysis. As a result the atmospheric half life time of nitro-PAHs ranges from less than an hour to

several days, depending on atmospheric conditions like temperature, sunlight intensity, on their

structure and on the concentrations of reactive compounds in the air (Keyte et al. 2013).

Key
Winter
Summer
X Molecular weight in g/mol
Y Fraction in particulate phase

Figure 3 — Nitro-PAHs gas/particle partitioning according to their molecular weight

(Albinet et al., 2008a)
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Figure 4 — Particle size distribution of 4 nitro-PAHs on a traffic (a – d) and suburban (e – h) site

in the Paris region (France) (Ringuet et al., 2012c). a, e: 1-nitronaphthalene; b, f: 9-

nitroanthracene; c, g: 2+3-nitrofluoranthene; d, h: 1-nitropyrene
3.1.3 Toxicity/mutagenicity

As they act as direct mutagens the mutagenic potential of nitro-PAHs can be 100 000 times greater than

that of PAHs (Durant et al., 1996; Durant et al., 1998; Enya et al., 1997; Hannigan et al., 1998; Lewtas et

al., 1990; Schuetzle, 1983; Landvik et al., 2007; Øvrevik et al., 2010). Four-ring nitro-PAHs seem to be

the most toxic substances (Durant et al., 1996; Durant et al., 1998; Finlayson-Pitts and Pitts Jr, 1986).

Overall, results from mutagenicity tests on bacteria (Ames test, Salmonella typhimurium) and on human

cells (h1A1v2 cells) showed that 3,6-dinitrobenzo[a]pyrene, 3,7-dinitrofluoranthene, 3,9-

dinitrofluoranthene, 6-nitrochrysene, 1- and 4-nitropyrene, 1,6-dinitropyrene and 1,8-dinitropyrene

(the most powerful mutagens described in the literature) had the highest mutagenic activities

(Environmental Health Criteria (EHC) 229, 2003; NTP, 2011; Enya et al., 1997; Pedersen et al., 2004;

Pedersen et al., 2005).

Nitro-PAHs contributions to the mutagenic and/or carcinogenic activity of atmospheric inhalable

particles were evaluated in the range 14 % to 50 % by different authors (Albinet et al., 2008a; Bandowe

et al., 2014; Finlayson-Pitts and Pitts Jr, 2000; Kawanaka et al., 2008; Taga et al., 2005).

Substances with a coplanar nitro group are more carcinogenic than those with a perpendicular nitro-

group. Dinitro-PAHs generally are more mutagenic than the mono-substituted compounds.

3.1.4 Carcinogenicity

Since the 1960s, evidence has increasingly supported the theory that chemical carcinogens (e.g. PAHs

and nitro-PAHs) are metabolized via oxidative pathways to produce electrophilic reactive

intermediates (e.g. nitrenium ions and epoxides) that react covalently with DNA and possibly with other

cellular nucleophiles. Nitro-PAHs seem to be less carcinogenic than their parent PAHs (EHC 229, 2003;

IARC, 2013; NTP, 2011; Benbrahim-Talaa et al., 2012). Different pathways seem to be possible for

carcinogenic activity. If the nitro-PAHs contain a “bay region” similar to benzo[a]pyrene and

benzo[a]anthracene their carcinogenicity is similar to the mechanisms described for the non-

substituted substances: After formation of an dihydroepoxide in the “bay region” this reactive

intermediate forms DNA adducts which are considered to be the first step causing carcinogenicity. If the

nitro group of these substances is oriented parallel to the aromatic core of the substances, their

carcinogenicity is not much lower than that of the non-substituted substances, but a perpendicular

orientation of the nitro group largely attenuates the carcinogenicity of the compounds (Fu et al., 1994;

Fu et al., 1998; Vogt et al., 2009; McDonald et al., 2004).
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For some nitro-PAHs another pathway of carcinogenic action is postulated (Fu et al., 1994): The nitro

group is partly reduced to a hydroxylamine derivative which after esterification (e.g. acetylation) forms

a nitrenium ion, which reacts with DNA to form an adduct, which can cause carcinogenicity.

Additionally nitro-oxy-PAHs seem to be more toxic than oxy-PAHs or nitro-PAHs (Helmig et al., 1992a;

Helmig et al., 1992b). For example, 3-nitrobenzanthrone is described as one of the the most potent

mutagens and a potential carcinogen identified in diesel exhaust and ambient particulate matter (Arlt,

2005; Enya et al., 1997; Feilberg et al., 2002; Nagy et al., 2005; Phousongphouang and Arey, 2003). A list

of the classification of the carcinogenicity of several nitro- and oxy-PAHs is given in Annex B.

3.1.5 Measurement
3.1.5.1 Sampling from ambient air

Nitro-PAHs with 4 rings or more are particle bound. For these substances sampling procedures for

particulate matter (e.g. PM and PM , as described in EN 12341) are suitable. In order to collect more

10 2,5

volatile compounds, a combination of a filter with, e.g. PUF as described in ISO 12884 is necessary.

Reaction of PAHs with oxidants in combination with nitrous oxides may lead to positive artefacts during

sampling. Rearrangements of the nitro groups of the compounds during sampling are also possible.

The formation of nitro-PAHs via heterogeneous reactions with only nitrogen oxides has been shown to

be unfounded in case of ambient air sampling (Arey et al., 1988; Dimashki et al., 2000). Only at elevated

temperatures and extremely high concentrations of NO direct nitration of PAHs is possible (Carrara et

al., 2010; Carrara et al., 2011).

Studies delivered different results about the reactions of nitro-PAHs during sampling, possibly leading

to artefacts, but until now no clear results about reactions of nitro-PAHs during sampling and about

methods to inhibit these reactions have been published.
3.1.5.2 Analysis

A review paper on the analysis of nitro-PAHs in environmental samples was proposed by Zielinska and

Samy (Zielinska and Samy, 2006). The analytical procedure of collected samples includes an extraction

step prior to nitro-PAHs quantification. Several extraction procedures are reported (Soxhlet,

microwaves, pressurized liquid extraction, sonication) using different solvents or solvent mixtures

(dichloromethane, hexane, toluene, acetone). A purification step (e.g. SPE (solid phase extraction)) shall

also be included. Alternatively to solvent extraction methods, SFE (supercritical fluid extraction) using

pure CO is also reported in numerous studies (Castells et al., 2003; Lewis et al., 1995). The use of

solvent-free extraction techniques was also reported in different papers with thermal-desorption (TD)

coupled with GC-ToF-MS or GC × GC-ToF-MS (Fushimi et al., 2012; Orasche et al., 2011) and laser

desorption/ionization coupled to ToF-MS (LD-LI-ToF-MS) (Dotter et al., 1996). Finally, as an alternative

to traditional procedures, recently Albinet et al. (2014) reported the use of QuEChERS-like (Quick Easy

Cheap Effective Rugged and Safe) extraction approach for the analysis of nitrated and oxygenated PAHs.

Analysis of nitro-PAHs is generally achieved using GC-MS, GC-NICI-MS, HPLC-FD (fluorescence

detection), HPLC-CD (chemiluminescence detection), LC-MS, LC-MS-MS.

Because of its great sensitivity and selectivity towards the nitro group, GC-NICI-MS using methane as

the reactant gas minimizes the analytical interferences from co-eluted compounds by significantly

improving signal-to-noise ratios (Bezabeh et al., 2003). Relative to GC-MS in EI ionization mode, a

sensitivity improvement approaching two orders of magnitude could be obtained. Limits of detection in

the lower picogram and femtogram ranges have been reported for this method (Albinet et al., 2006;

Bezabeh et al., 2003). Actually, this analytical technique constitutes probably the best cost/performance

compromise for the analysis of nitro-PAHs in ambient air samples. Maintenance requirement are mainly

linked to the fouling of the MS source (due to the use of reagent gas for ionization) inducing a loss of

sensitivity, but progress has been made enhancing the lifetime of the MS source.
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SIST-TP CEN/TR 16998:2017
CEN/TR 16998:2016 (E)

HPLC-FD after reduction of the compounds to the corresponding amines or HPLC-CD is also widely used

notably by Japanese research teams (e.g. Hayakawa et al., 1999; Hayakawa, 2000; Kawanaka et al.,

2008; Nassar et al., 2011; Ohno et al., 2009; Tang et al., 2005, see also references in Zielinska and Samy,

2006). Greater precision and selectivity is obtained by increased automation of these kinds of analytical

techniques. Limits of detection in the range of 1 pg to 10 pg injected have been reported for this method

(Hayakawa et al., 1999; Hayakawa, 2000; Kawanaka et al., 2008; Ohno et al., 2009; Schauer et al., 2003;

Tang et al., 2005; Zielinska and Samy, 2006 and references therein). The complexity and maintenance

requirements of these kinds of systems (i.e. time automated switching valves, multiple plumbing

components, and consumables), does implicate a need for highly specialized procedures with

customized components and protocols.

The use of LC-MS and LC-MS-MS is also reported in several papers (e.g. Mirivel et al., 2010; Schauer et

al., 2004; Zielinska and Samy, 2006 and references therein) but the sensitivity of this technique is still

not optimal for nitro-PAHs analysis. Detection limits are 3 to 100 higher (5 pg to 100 pg injected) than

those reported for GC-NICI-MS analytical systems. Only the possibilities of unknown species are a

significant advantage of this method but the investment and working costs are really higher than for the

other analytical techniques.

An example of an SOP dealing with sampling and analysis of nitro- and oxy-PAHs are given in Annex A.

3.2 Oxy-PAHs
3.2.1 Sources
3.2.1.1 General

Oxy-PAHs (ketones, aldehydes, hydroxy-PAHs) are both directly emitted from combustion processes

and formed in the atmosphere as by-products of the photolysis of parent PAHs or photochemical

reaction between parent PAHs and atmospheric oxidants (Vione et al., 2004; Yu, 2002).

3.2.1.2 Direct emissions

Major direct sources are diesel and gasoline combustions, biomass burning, waste combustion, coal and

fuel burning, and production of charcoal (Abas et al., 1995; Akimoto et al., 1997; Cho et al.

...

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