Upload
others
View
2
Download
0
Embed Size (px)
Citation preview
Chemical reactions in ventilation systems Ozonolysis of monoterpenes
Jerker Fick
Akademisk avhandling
Som med tillstånd av rektorsämbetet vid Umeå universitet för erhållande av
Filosofie Doktorsexamen vid Teknisk-Naturvetenskapliga fakulteten i Umeå,
framlägges till offentlig granskning vid Kemiska institutionen i KBC-huset,
hörsal KB3B1, fredagen den 3:e oktober 2003, klockan 13:00.
Fakultetsopponent: Charles Weschler, Adjunct Professor, Department of
Environmental and Community Medicine, University of Medicine and Dentistry
of New Jersey, Robert Wood Johnson Medical School, New Jersey, USA.
Copyright © 2003 Jerker Fick
Department of Chemistry Environmental Chemistry
Umeå University SE-901 87
Sweden
ISBN 91-7305-511-5
Printed in Sweden by VMC, KBC. Umeå University. Umeå 2003.
ABSTRACT
Chemicals in indoor air, either emitted from a source or from a reaction, have been suggested to cause ill health in buildings. However, no clear correlations between exposure and health effects have been made.
In this thesis we studied the reaction between monoterpenes, a group of biogenic unsaturated C10 hydrocarbons, and ozone. Ozonolysis of monoterpenes was used as model reactions for unsaturated compounds in ambient air. Also the products formed from these reactions have been suggested as important participants in the occurrence of discomfort and ill health in buildings.
To enable a reliable and sensitive measurement of ppb-ppt levels of monoterpenes and the formed products in the presence of ozone an evaluation of available scrubber materials was made. Potassium iodide was shown to remove ambient levels of ozone and have a recovery of >95% for all monoterpenes and formed products included in the investigation.
Experimental conditions showed to have a large impact on the initial steps of the ozonolysis, and also on the composition of the formed products. We showed that water plays an important and complex role both in the initial stage of ozonolysis of ∆3-carene and in the formation and composition of products from the ozonolysis of α-pinene. The use of experimental design facilitated the evaluation of the investigated reactions. We showed that the formation of OH radicals could be studied using multiple linear regression models and that the presence or absence of OH radicals had a profound impact on the formation of many of the formed products. We also made an observation of the lack of formed OH radicals in the ozonolysis of limonene and discussed probable causes of this observation.
Despite the short reaction times and the ambient levels of ozone and monoterpenes used in our experiments we showed that a number of oxidation products were formed, and that the reaction rate is significantly increased in a ventilation system. This formation is underestimated by theoretical calculations and leads to high amounts of known irritants in the indoor air. We showed that theoretical calculations underestimate the formation of these oxidation products 3-13 times, depending on ventilation system and monoterpene.
Keywords: Monoterpene, Ozone, OH radical, Ozonolysis, Ventilation, Potassium Iodide, Experimental Design, Heat Exchanger.
LIST OF ABBREVIATIONS
ATD Automated Thermal Desorption BSTFA N,O-bis(trimethylsilyl)-trifluroacetamide ECI Excited Criegee Intermediate FID Flame Ionization Detector GC Gas Chromatograph MLR Multiple Linear Regression MS Mass Spectrometer PCI Positive Chemical Ionization PFBHA O-(2,3,4,5,6-pentafluorobenzyl) hydroxy amine PFS Poly(1,4-phenylene sulfide) ppb Parts Per Billion RH Relative Humidity SBS Sick Building Syndrome SCI Stabilized Criegee Intermediate VOCs Volatile Organic Compounds WHO World Health Organization LIST OF PAPERS This thesis is based on the following papers, which will be referred to with Roman numerals (I-IV) I. Ozone removal in the sampling of parts per billion levels of terpenoid
compounds: An evaluation of different scrubber materials. Fick, J., Pommer, L., Andersson, B., Nilsson, C. Environmental Science & Technology, 2001, 35, 1458-1462.
II. A study of the gas-phase ozonolysis of terpenes: the impact of radicals formed
during the reaction. Fick, J., Pommer, L., Andersson, B., Nilsson, C.
Atmospheric Environment, 2002, 36, 3299-3308. III. Effect of OH radicals, relative humidity, and time on the composition of the
products formed in the ozonolysis of α-pinene. Fick, J., Pommer, L., Andersson, B., Nilsson, C.
Atmospheric Environment, 2003, 37, 4087-4096.
IV. The effect of mechanical ventilation systems on the chemistry in the supply air.
Fick, J., Pommer, L., Andersson, B., Nilsson, C. Submitted
The published papers are reproduced with kind permission from the American Chemical Society (paper I) and Elsevier Science (papers II, III).
TABLE OF CONTENTS
1. INTRODUCTION…………………………………………………. 1
2. SICK BUILDING SYNDROME………………………………….. 2
3. OZONE……………………………………….…………….……... 3
4. MONOTERPENES……………………………………………….. 6
5. OZONOLYSIS ………………………………………………...…. 7 5.1. Initial steps…………………………………………………….. 7 5.2. Uni or bimolecular reactions…..………………………..……... 8 5.3. Oxidation by OH radicals………………………..………….… 10 5.4. Ozonolysis of monoterpenes….……………………….………. 11 5.5. Oxidation in the atmosphere…………………………………... 15
6. EXPERIMENTAL DESIGN..……………………………………… 15 6.1. Evaluating experimental designs……………………………… 16
7. MATHEMATICAL MODELLING…………………………….…. 17
8. SAMPLING…………………………………………………………. 17 8.1. Tenax TA………………………………………….……….…. 18 8.2. Gas bubbler…………………………………….……….…….. 18 8.3. Sampling in the presence of ozone……………………………. 19
9. ANALYSIS..…………………………………………………….….. 19 9.1. ATD-GC-FID…………………………………………………. 19 9.2. GC-PCI-MS.…………………………………………………... 20
10. VENTILATION SYSTEMS.……………………………………… 20 10.1. Chemical reactions in ventilation systems………………….... 22
11. CONCLUSIONS AND FUTURE WORKS………………………. 24
12. ACKNOWLEDGEMENTS………………………………………. 26
13. REFERENCES…………………………………………………….. 27
- 1 -
1. INTRODUCTION The basis of this thesis is that chemicals in indoor air, either emitted from a source or
products from a reaction, have a profound effect on human health. This is not a new
theory. Seneca was frequently advised to leave Rome by his physician and he wrote
to his friend Lucilius in 61 AD that as soon he left Rome's oppressive fumes he felt
better (1). Many reports, observations and regulations since connect air pollution with
adverse health effects (2). For example, Bernardino Ramazzini reported in the
beginning of the 18th century that small rooms become filled with smoke from oil
lamps and gases emitted from humans and that these pollutants penetrate the brain
skull (3).
The specific chemicals we have studied in this thesis are monoterpenes, unsaturated
biogenic hydrocarbons, and the products formed when these react with ozone. We
chose these reactions because they can be used as model reactions for a wide variety
of chemical compounds. Also the products formed from these reactions have been
suggested as participants in the occurrence of discomfort and ill health in buildings
(4, 5). Furthermore, these reactions were studied in an authentic ventilation system to
elucidate the impact of such systems on the chemical reactions that occur in the
ambient atmosphere.
The aim of this thesis was to study the chemical reactions that occur in the ventilation
systems. This aim included:
■ The development of a robust and accurate method for air sampling of
monoterpenes and oxidation products in the presence of ozone. (paper I)
■ Studying the influence of different factors on the oxidation of monoterpenes. (paper
II)
■ Making theoretical calculations of the reactions to be able to compare with and/or
verify the experimental results. (papers II, IV)
■ To investigate which products are formed and what affects the composition of
these. (paper III)
■ Examining the impact of an authentic ventilation system on the oxidation of
monoterpenes. (paper IV)
- 2 -
2. SICK BUILDINGS SYNDROME Historically, the problem with poor indoor air quality was more apparent than
currently. Soot from the ceilings of prehistoric caves provides evidence of the high
concentrations of pollutants that are correlated with the use of open fires in settings
with inadequate ventilation (6). This problem is still the major indoor air quality
problem in the developing countries (7-9). Today, half of the world's population is
exposed to indoor air pollutants from the burning of solid fuels for cooking and
heating, and this exposure is estimated to cause 36% of all lower respiratory
infections and 22% of chronic obstructive pulmonary diseases (10). That this also
was a problem historically was demonstrated by Wells (11) who showed that 1-6% of
the early Britons suffered from sinusitis, an inflammatory disease of the sinus
cavities, that was caused by polluted air indoors. Several observations of poor indoor
and outdoor air have been reported from antiquity and forward, and several reports
clearly stress the relationship between air pollution and health (2). The severe
pollution episodes in London 1873 and 1952, and the increased pollution in Los
Angeles in the 1940's emphasized the hazards of air pollution and intense research
and several regulations followed.
Prior to the 1970's, however, the interest of indoor air quality in the scientific
community was low (12). The name Sick Building Syndrome (SBS) refers to the
diverse affliction that was observed on a large scale in the wake of the oil crises in the
1970's, when the buildings were modified to be more energy effiecient (13, 14). The
term Sick Buildings and Sick Building Syndrome were defined by the World Health
Organization (WHO) in 1983 (13).
SBS is a diverse affliction that includes symptoms like mucous irritation (e.g.,
irritation of the eyes, nose, and throat, skin irritation, odor and taste complaints),
neurotoxic effects (e.g., fatigue, lethargy, headache, nausea, and reduced memory and
concentration), and nonspecific reactions (e.g., chest sounds and asthma-like
symptoms) (13, 15, 16). WHO estimated that 30% of new buildings have poor air
quality (15, 17). SBS has been estimated to affect 19 to 80% of the workers in studies
from North America and Europe (18-20), and is considered to have a multifactorial
etiology that includes exposure to volatile organic compounds (VOCs), bioaerosols,
- 3 -
environmental tobacco smoke, electromagnetic fields, exposure to stress,
psychosocial factors, and other environmental and personal factors (19, 20).
The similarities of the symptoms of the exposure to high levels of VOCs and SBS
(21) have emphasized the theory that VOCs contribute to SBS although no clear
correlations have been made (20, 22). A recent study by Pommer et al. (23) showed a
correlation between the prevalence of SBS and some VOCs, relative humidity, and
building factors. Since the exposure to VOCs is mainly influenced by the ventilation,
a lot of attention have been focused on the correlation between SBS and factors like
ventilation rate, emissions from materials or debris in the ventilation system, types of
ventilation system, etc. (24-26). Increased ventilation rates have been associated with
decreased complaints of SBS and poor air quality (25, 27), but have also been shown
to have no effect (24, 28). Air conditioning was shown to increase the prevalence of
SBS symptoms by 30 to 200% relative to natural ventilation (26).
A possible additional factor is the formation of chemical reaction products (4, 5, 29),
mostly aldehydes, ketones, and carboxylic acids (30-32), but also particles (33-35),
which decrease the quality of the indoor air drastically (36). The oxidized products
are known irritants (37-40), allergenes (41), and some are even carcinogenic (42).
Kreiss et al. (40) presented a study of workers at a microwave-popcorn plant that had
been exposed to 2,3-butanedione and other compounds used as flavoring agents.
They showed a marked increase in respiratory and systemic symptoms and clearly
correlated this to the exposure to the chemicals. Exposure to VOCs indoors has also
been suggested to contribute to the increased prevalence of asthma (14).
3. OZONE Ozone was discovered in 1840 by C. F. Schönbein by anodic oxidation of acidified
water (43) and he named it ozone after the Greek word ozein, to smell, because of its
odor. The correct chemical structure was later elucidated by W. Odling in 1861 (44)
and confirmed by R. C. Brodie in 1872 (45). Ozone is a very pale blue gas, that forms
a blue liquid (b.p. -111.9 °C) and a violet-black solid (m.p. -192.5 °C) (46). Ozone
has a bent triatomic structure with an apex angle of 117° and a bond length of 1.27 Å
(47-49). The ozone structure is best described as a resonance species with four
contributors (50, 51) as shown in figure 1.
- 4 -
Figure 1. Resonance structures of ozone.
Ozone is a strong oxidant and reacts with most organic compounds primarily as an
electrophile (51, 52). In acid solutions the oxidizing potential is only surpassed by a
few reactive species such as fluorine, OH radical, etc. (53). Ozone also reacts with
compounds in the gas-phase. At room temperature, however, the gas-phase reaction
rates constants for most organic compounds are too low to lead to any significant
oxidation, with the exception of alkenes (29, 54). Alkenes reacts readily with ozone
with rate constants in the range of 10-16 - 10-18 cm3 molecule-1 s-1 at room temperature
(54), which leads to a significant oxidation in the ambient atmosphere indoors and
outdoors.
Ozone has a characteristic odor, detectable at 10 parts per billion (ppb), and is very
toxic (55). Concentrations exceeding 120 ppb have been suggested to affect healthy
adults, but children and other sensitive individuals such as asthmatics react at lower
concentrations (55, 56). Ozone has been shown to cause damage to the lung, blood
and central nervous system (57). This damage is caused by an inflammatory process,
which liberates free radicals (58), as well as by formed oxidation products (59).
Ozone also causes damage to vegetation and the levels of ozone in the ambient air are
high enough to have an adverse effect on plants (60). Exposure to ozone leads to
effects on the yields and quality of cereal crops (61, 62), and cause reduction in
growth and biomass of forest trees (63, 64). Ozone exposure also leads to an
increased susceptibility to secondary stress (64) and can alter the composition of
natural ecosystems (65).
Ozone is formed in the stratosphere (figure 2) by the dissociation of O2, through a
mechanism first proposed by Chapman (66) as presented in equation 1, 2.
O2 + hv → O + O (1)
O + O2 + M → O3 + M (2)
Where hv = < 242 nm and M is a neutral third body (usually N2 or O2) (67).
- 5 -
Figure 2. The lower part of the atmosphere.
Most of the ozone is present in the stratosphere at altitudes of 15-35 km in the so-
called ozone layer. This ozone layer absorbs most of the suns ultraviolet light (hv
=230-320 nm), equation 3 (67).
O3 + hv → O2 + O (3)
Ozone is also present in the troposphere (figure 2). Some is transported down from
the stratosphere through folding events and diffusion, and some is produced by
dissociation of NO2. Ozone production in the troposphere is governed by a complex
interplay between OH radicals and the VOCs/NOx ratio, where an increase in VOCs
leads to more ozone and an increase in NOx can either decrease or increase the ozone
level depending on the ratio (67). This means that the level of ozone is higher in
polluted urban areas and lower in rural areas. Ozone levels in remote rural areas
average between 20-45 ppb (68, 69) but in polluted urban areas the ozone level can
reach as high as 400 ppb (67). Ozone levels increase with approximately 1% a year
(70, 71) and the levels of tropospheric ozone has more than doubled in Europe since
the beginning of the 20th century (68). This is due to increased levels of pollutants in
the troposphere, mainly from transportation (67).
Ozone is also present indoors at levels of 20-80% of those outdoors (72-75). Indoor
concentration of ozone is affected by the ventilation and air exchange rates (72, 76)
and follows closely the concentration of the outdoors levels of ozone (75). Ozone
- 6 -
reacts rapidly with sinks in the indoor setting like carpets and other surfaces (75, 77-
80), which lowers the ozone levels indoors.
4. MONOTERPENES Monoterpenes is a group of C10 biogenic alkenes, which are emitted by vegetation
(figure 3). In some families such as the Pinaceae (e.g., pine, fir) and Lamiaceae (e.g.,
mint, basil) almost all species emit monoterpenes; they are also emitted by many
other species from a wide range of families (81, 82). The monoterpenes have boiling
points in the range 150°–185° C, and are all very fragrant with an odor threshold in
the ppb range; they are often used as additives in cleaning products (83).
α-pinene β-pinene Limonene ∆3-Carene ∆2-Carene
Myrcene Terpinolene Camphene Sabinene β-Phellandrene
Figure 3. Some monoterpenes.
Monoterpenes have been shown to deter herbivores and attract pollinators (81, 84).
Monoterpenes were suggested to protect against thermal stress and have been shown
to increase the thermotolerance of the photosynthetic apparatus by stabilizing the
thycaloid membranes (85). Peñuelas and Lluisà (86) showed that monoterpenes also
protected against photodamage, especially at elevated temperatures.
Guenther et al. (87) calculated that monoterpenes account for approximately 1.0
x1013 g carbon of the annual emission of biogenic hydrocarbons in North America
- 7 -
and approximately 1.27 x1014 g carbon year-1 globally (88). Monoterpenes account
for 10% of the total global emission of non methane volatile organic compounds,
which is estimated at approximately 1.3x1015 g carbon year-1 (67, 88), and at the
same level as the total anthropogenic contribution (67). In a typical coniferous forest
the monoterpene concentration is 0.01-5 ppb depending on the time of day, season
and location (89, 90). Temperature has the greatest influence on the emission as it
increases the production and emission rates of most monoterpenes exponentially up
to a maximum, beyond which enzyme degradation and other physiological processes
changes the emission (91, 92). This strong dependency on temperature has raised the
question if the global warming has started to affect the amount-emitted of
monoterpenes (81). A recent calculation stated that global warming over the last 30
years has increased the biogenic volatile organic compounds emission by 10% and a
rise of 2-3 ºC this century would results in an additional 30-45% (93).
Monoterpenes are also present indoors due to emissions from floors, walls and
furniture made out of wood, as well as transport from the outdoor air (22). The indoor
levels of monoterpenes actually often exceed that of the outdoor air (22, 94), and in
new/newly furnished buildings the VOCs and monoterpenes levels can be
considerable elevated (22). Levels above 400 ppb α-pinene have been detected in
specific indoor settings (22).
5. OZONOLYSIS
The gas-phase reaction between ozone and alkenes is a complex multi-step reaction
(95, 96) that has received a lot of attention recently because it plays a major role in
various urban air pollution phenomena, e.g., formation of particles (33, 35, 97-99),
and as important precursors in the formation of tropospheric ozone and OH radicals
(100-107).
5.1. Initial steps.
The reaction starts with a 1,3-dipolar addition of ozone, which yields a 1,2,3-
trioxolane product (96, 108, 109), which is shown in figure 4. This 1,2,3-trioxolane
product is thermally unstable and rapidly rearranges into a vibrationally excited
- 8 -
carbonyl oxide called the excited Criegee intermediate (ECI) and a carbonyl
(aldehyde or ketone depending on the substituents) (50, 108-111), figure 4.
R
RR
ROO
OR
R
OOO
R
R
R R
OO
R R
O
+
#
.
.
Figure 4. Initial steps of ozonolysis.
Based on structural calculations (112, 113), ECI adopts the carbonyl oxide structure.
Adam et al. (114) calculated that the activation energy prevents a cyclization of
carbonyl oxide to dioxirane. The initial steps of the ozonolysis are now reasonably
understood even though significant uncertainties remain, e.g., it has been suggested
that the addition of ozone may not only be a concerted mechanism but also a partial or
stepwise addition (115).
5.2. Uni or bimolecular reactions
ECI can either be collisionally stabilized by a third body (nominated M in figure 5),
decomposed or isomerized (figure 5).
RR
HOO
O O
R R
RR
O
O O
R RR R
OO
R R
OO
R R
OO
R R
OO#
#
#
M
#
OH. + .
Products
or
#
#
.
.
#
.
.
#
.
.
.
.
.
Figure 5. Different reaction pathways for excited Criegee intermediate (ECI).
- 9 -
There are still some questions about the structure of the stabilized Criegee
intermediate (SCI). Theoretical calculations indicate it can form a carbonyl oxide or a
dioxirane (116). Please note that the SCI may not be a carbonyl oxide but a dioxirane
(figure 5). Yields of 3-40% (117-122) of SCI have been reported. These
measurements are all based on the detection of formed products and not on direct
observations. Kroll et al. (107, 123) observed a pressure dependency in the OH
radicals formation for a number of small alkenes. Their method includes the direct
detection of OH radicals with laser-induced fluorescence at various pressures and at
very short reaction times (107). Kroll et al. (107, 123) also states that larger alkenes
will have more vibrational modes and therefore be even more susceptible to
collisional stabilization and report a weak but existent trend of this in their series of
alkenes. Other groups (124, 125) have also reported observations of pressure
dependant reactions. These findings imply that most of the ECI from the ozonolysis of
monoterpenes will be collisionally stabilized and put the emphasis on possible
consecutive bimolecular reactions.
SCIs have been reported to react with H2O (115, 122, 126-128 and paper III), SO2
(115, 119, 126), aldehydes (115, 126), and NOx (115, 126). Some authors have even
suggested that the SCI can react with alkenes (96, 129 and paper II). Crehuet et al.
(130) calculated that the reaction between a SCI and an alkene would proceed through
a similar transition state as that of the ozone-alkene reaction, and yield 1,2-
dioxolanes. A number of other reaction pathways between SCI and various
compounds have been reported (96, 122, 127, 131 and paper III), and the most
relevant reaction is the reaction between SCI and H2O. Even though the reaction rate
is slow (an estimated upper limit at 10-16 cm3molecule-1s-1) (132), H2O is so abundant
in the atmosphere that it will dominate over all other reaction pathways. Ryzhkov and
Ariya (128) suggested recently that the SCI reacts with a water dimer and that this
pathway is more energetically favorable than the reaction with water as calculated by
other groups (131, 133). SCIs that reacts with water form the corresponding α-
hydroxy hydroperoxide (122, 127, 134-137) as shown in figure 6.
- 10 -
R R
OHHOO
Figure 6. An α-hydroxy hydroperoxide.
α-Hydroxy hydroperoxides have been isolated in the atmosphere (138) but they
dissociate and form a variety of products (135, 139, 140).
One of the unimolecular reactions available to the ECI is the isomerization and
formation of an excited 5 membered hydroperoxide intermediate, which dissociate
and forms an OH radical and a peroxy radical (104, 110) as shown in figure 5. This
pathway requires an alkyl group adjacent to the ECI, i.e., the ECI needs to be
monosubstituted syn or disubstituted. Experimental data from Kroll et al. (107, 123)
indicate that at atmospheric pressure most of the formed OH radicals are formed from
the thermal dissociation of SCI. Kroll et al. (107, 123) state that even though almost
all of the ECI is stabilized, unimolecular reactions will dominate the reaction scheme
and will primarily lead to thermal dissociation to form OH radicals (123, 141).
The ECI may also ring closure to dioxirane (100, 110) as shown in figure 5. This
route is also called the "hot ester channel". The isomerization to dioxiranes seems to
be hindered if the CI is disubstituted or monosubstituted syn, but may occur as in the
unsubstituted case (100, 123). Calculations show that alkyl substituted bisoxy radicals
prefer the ester rearrangement decomposition (142), but the further fate of this
reaction pathway is unknown (123).
5.3. Oxidation by OH radicals
The major initial reaction pathway involves OH radical addition to either carbon in
the double bond to form β-hydroxyalkyl radicals (54, 143) (figure 7).
R
RR
RR
RR
ROH
OH. + .
Figure 7. Addition of OH radicals.
- 11 -
In addition to the addition pathway, H-atom abstraction from the C-H bond of alkyl
substituents adjacent to the double bond occurs as a minor process (54, 143) (figure
8).
R
RR
R
R
RR
R
OH. + + H2O.
Figure 8. H-Abstraction by OH radicals.
5.3. Ozonolysis of monoterpenes
The ozonolysis of monoterpenes has been studied extensively and the reaction rates
are well known (54) and are presented in table 1.
Table 1. Reaction rates with ozone and OH radical formation yields of some monoterpenes.
Monoterpenes Reaction rate a Lifetime b OH radical
formation c
α-Pinene 86.6 4.6 h 0.85
β-Pinene 15 1.1 day 0.35
Limonene 200 2.0 h 0.86
∆3-Carene 37 11 h 1.06
∆2-Carene 230 1.8 h d
Myrcene 470 50 min 1.15
Terpinolene 1880 12 min 1.03
Camphene 0.9 18 days <0.18
Sabinene 86 4.6 h 0.26
β-Phellandrene 47 8 h 0.14
a 1018 x k (at 298 k) (cm3 molecule-1 s-1) (54).
- 12 -
b Time for decay of compound to 1/e (37%) of its initial concentration at an ozone concentration of 28 ppb (143) c Molar yield of OH radicals (102). d No value reported.
The monoterpenes react readily with ozone and the ozonolysis also generates OH
radicals (table 1). Any system involving ozonolysis of monoterpenes therefore
includes the presence of OH radicals. These OH radicals can be quenched, i.e., a
compound is added that reacts faster with the OH radicals than the compounds studied
(102, 103, 144), in order to study the effect of ozone itself.
This thesis focused on the OH radical production (paper II) and the experimental
settings impact on the initial ozonolysis (paper II) and the product composition (paper
III).
In paper II we studied the OH radical formation and the impact of the experimental
settings on the initial ozonolysis of three monoterpenes, α-pinene, ∆3-carene and
limonene. We made theoretical mathematical calculations, based on known reaction
rates, of the various reactions in order to compare predicted amounts reacted with our
experimental data. When comparing the experimental results with the predicted
values it was shown that the ozonolysis of the different monoterpenes was faster than
predicted for all monoterpenes. We showed that α-pinene, ∆3-carene and limonene
reacted 1.37, 3.79, and 1.61 times more than predicted, respectively. A hypothesis that
this was due to reactions on surfaces was presented.
We also showed that the OH radical formation of both α-pinene and ∆3-carene were
possible to study using an experimental design. We observed that the ozonolysis of
limonene apparently did not produce OH radicals; an observation that directly
contradicts other studies (102, 145, 146) and that which is not consistent with the
most acknowledged theory (104, 147). An alternative reaction pathway between the
SCI from the ozonolysis of limonene and limonene itself was suggested-a pathway
that has been proposed previously (96, 129, 130).
- 13 -
In paper III we focused on the products from the reaction between α-pinene and
ozone, and the impact of the experimental settings on the composition of these
products. The reported products from the reaction between α-pinene and ozone are
shown in table 2.
Table 2. Detected products in published chronological order from the ozonolysis of α-pinene. References in parenthesis.
O
O
Pinon aldehyde
O
O Norpinon aldehyde
O
O
OH
Pinonic acid
OH
O
O Norpinonic acid
O
O
Glyoxal
(30, 31, 97, 136, 148-156) Paper III
(31, 148, 150, 152, 154, 155) Paper III
(31, 148-152, 154, 155) Paper III
(31, 148, 150, 152, 154, 155) Paper III
(149, 150) Paper III
O
α-pinene oxide
OOH
O
OH
Pinic acid
OO
Methyl glyoxal
C9H14O3 Norpinonic acid isomer
OH
O
O
OH
Norpinic acid
(136) (31, 150-152, 154, 155) Paper III
(150) Paper III
(31, 150-152, 154, 155) Paper III
(31, 151, 152, 154, 155)
O
O
OHOH
10-Hydroxy pinonic acid
O
OHO
a
O
O
b
O
O
O
c
C10H14O3
(31, 151, 152, 154, 155)
(31, 152, 155)
(31, 152, 154, 155)
(31) (31, 152, 154, 155)
a 3-formyl-2,2-dimethylcyclobutanecarboxylic acid
b 2,2-dimethylcyclobutane-1,3-dicarbaldehyde
c (3-acetyl-2,2-dimethylcyclobutyl)methyl formate
Other products that have been reported are CO (148), CO2 (148), formaldehyde (148,
149, 157), formic acid (148, 157), acetone (149, 157, 158), and C10H16O (136). Jaoui
and Kamens (154, 155) reported some additional products including 1 and 10-
- 14 -
hydroxypinon aldehyde and campholene aldehyde but it should be noted that their
experiments were conducted in the presence of both ozone and OH radicals.
Oxidation by OH radicals also generates pinon aldehyde as the most prominent
product (32, 159-161) and a variety of additional products have been reported e.g.,
campholene aldehyde (32), hydroxy and dihydroxycarbonyls (159, 161, 162) and
acetone (159). OH radicals can also react with the formed products and form a wide
variety of additional products (163-168).
In paper III we investigated how experimental settings affected the composition of the
products formed in the ozonolysis of α-pinene. We detected pinic acid, glyoxal,
methyl glyoxal, norpinonic acid and norpinonic acid isomer, pinonic acid, an
unidentified C4 dicarbonyl (C4H6O2), an unidentified C5 dicarbonyl (C5H8O2),
norpinon aldehyde, and pinon aldehyde (table 2). Rohr et al. (39) showed that
products from the ozonolysis of α-pinene have adverse effects on both the upper
airways and the pulmonary regions. That reaction products from various chemical
reactions, especially ozonolysis, can contribute to cause ill health in a population have
been suggested by several researchers (4, 5) and the findings of Rohr et al. (39)
strongly supports this theory.
We showed that water plays a pivotal role in the reaction scheme increasing the
reaction rate for some products (i.e., pinic acid, glyoxal, methyl glyoxal and pinon
aldehyde) and decreasing the yield of pinonic acid. Pinonic acid, norpinonic acid and
an isomer of norpinonic acid were shown to be more or less solely formed from the
reaction of α-pinene and OH radicals.
We also presented a novel route to the formation of pinic acid, which was supported
by experimental observations. In addition we presented a route to the formation of (3-
acetyl-2,2-dimethylcyclobutyl)methyl formate (table 2), a product that was observed
by Yu et al. (31).
- 15 -
5.5. Oxidation in the atmosphere
In principle all hydrocarbons in the atmosphere will eventually be oxidized and form
CO2 and H2O (67). This process is, however, a complicated and lengthy one, and a
wide variety of more or less stable products are formed (67, 143). A simplified
reaction sequence of the reaction between the OH radical and methane (67), the most
common and simple hydrocarbon in the atmosphere, illustrates this as presented in
equation 4-14.
CH4 + OH. → CH3
. + H2O (4)
CH3. + O2 + M → CH3O2
. + M (5)
CH3O2. + NO → CH3O
. + NO2 (6)
CH3O2. + HO2
. → CH3OOH + O2 (7)
CH3O. + O2 → HCHO + HO2
. (8)
HO2. + NO → NO2 + OH
. (9)
CH3OOH + hv → CH3O. + OH
. (10)
CH3OOH + OH. → HCHO + H2O + OH
. (11)
CH3OOH + OH. → H2O + CH3O2
. (12)
HCHO + OH. or hv → CO + H2 (13)
CO + OH. → CO2 + H
. (14)
The atmospheric fate of the more complex monoterpenes is not a straightforward
reaction pathway to CO2 and H2O. It is a complex reaction scheme that starts with
oxidation by ozone, NO3 or OH radicals, and includes the formation of particles,
radicals and stable products, which we have just begun to understand (143).
6. EXPERIMENTAL DESIGN Experimental design covers a number of techniques where the objective is to obtain as
much information as possible with as few experiments as possible (169). The scope is
to explain the change in response caused by variations in the different experimental
parameters when all the experiments are combined using multiple linear regression
- 16 -
(MLR). MLR is a statistical method that calculates a mathematical equation (a
model), using the parameters mean response differences between high and low
settings (169). Experimental designs have been used extensively in this thesis (papers
II-IV).
The experiments are done according to a planned design, where a full factorial design
yields the most information, and fractional design provides an option to decrease the
number of experiments with a minimum loss of information. Additional experiments,
so called centerpoints, are often added at the mean setting between the high and low
setting. Centerpoints enable the calculations of lack of fit and the experimental error
at 95% confidence interval, and also enables the detection of curvature.
6.1. Evaluating experimental design
The model correlates the settings of the different parameters with the corresponding
result. This correlation, which is measured by R2 and Q2, shows to what degree the
experimental data can explain the results. The R2 value shows how much of the
variance in the data is explained, and the Q2 value explains how well the model can
predict omitted values. This Q2 value is calculated by omitting existing values and
then replacing them with values calculated by the model; these values are then
compared, i.e., a cross-validation (169).
The results from the design are presented in two different ways, in contour plots and
as effect terms as shown in figure 9.
Figure 9. A contour plot of amount reacted (left) and effect terms (right) from an
investigation of the ozonolysis of α-pinene (paper II).
A contour plot is a graphic presentation of the MLR calculation at the specific
experimental settings and presents the response in the investigated region. The
designs enable us to make contour plots for all the regions within the experimental
settings. This is a powerful tool to study the details of the reaction and to predict the
- 17 -
amounts reacted at a specific setting. The effect terms show what impact the different
parameters had on the reaction, i.e., the change in impact when one parameter is
raised from the low to the high setting and all the other parameters are kept at their
centerpoints values. The main effects are calculated as the difference between the
averages of the high and low setting of the individual parameters. The interaction
effects are calculated as the difference in response between the average of both
parameters effects when both are at the high or low setting and the average in
response of the parameters effects when they are at opposite settings. Thus the
interaction term measures the synergistic effects of the main parameters, i.e., the
effect of one parameter depends on the level of another parameter.
7. MATHEMATICAL MODELLING The mathematical modeling in this thesis (papers II, IV) were used to predict the total
amount of reacted monoterpene and to calculate the quotient between the amounts of
monoterpene reacted with OH and ozone. A reaction model was formulated for the
different ozone-monoterpene reactions that included all the reactions that had an
impact on the initial stages of the ozonolysis. FACSIMILE, the software used (170),
calculated the partial differential equations of each chemical reaction and solved these
equations by integrating and averaging over small time intervals (cells). Some
approximations were made, but these were valid as long as the cells were small. The
mathematical models used in this thesis calculated only the initial step of the
ozonolysis and the reactions that were included in the reaction model were those that
had a direct effect on the amount of monoterpenes and the reactive species that
reacted with the monoterpenes. No attempt was made to calculate the distribution of
the various products because of the complexities and uncertanties involved.
8. SAMPLING A number of techniques that are available to sample VOCs in air are, cryogenic
methods, solid sorbents, gas bubblers, derivatisation on solid support
(chemosorption), whole air sampling, etc. Many of these methods are also possible to
combine in order to enhance the sampling efficiency for individual compounds (150,
171-176). Two of these methods, solid sorbent sampling using Tenax TA as
- 18 -
adsorbent (paper I, II, IV) and gas bubbler sampling (paper III) have been used in this
thesis.
8.1. Tenax TA
Tenax Ta is a 2,6-diphenylene oxide polymer, which is suitable for sampling VOCs
in the C7-C26 range (171, 176, 177) and is extensively used for sampling
monoterpenes (178). Tenax TA adsorbs the VOCs through dispersion interactions
supported by dipole-type interactions (179); however, this adsorption is a
physisorption process and enables recoveries of 100% (180, 181). Tenax TA is
hydrophobic and thermally stabile (176) but is prone to degradation in the presence of
ozone (182) and other reactive species (183).
8.2. Gas bubbler
Sampling with a gas bubbler was used in this thesis (paper III) to enable the detection
of oxidation products from the ozonolysis of α-pinene. Gas bubblers contain liquids
that extract compounds from the air sample that is pumped through and this method is
used for collecting polar, reactive and high-boiling compounds (171, 184, 185). This
method is also convenient to combine with different derivatizing methods (171, 184).
Yu et al. (150) reported a method that made it possible to simultaneously detect
products with a diverse range of functional groups and this method was used in paper
III. The method derivatizes carbonyls, alcohols, and acids and also derivatizes
multifunctional compounds. The carbonyls were derivatized using O-(2,3,4,5,6-
pentafluorobenzyl) hydroxy amine (PFBHA) and the acids and alcohols were
derivatized using N,O-bis(trimethylsilyl)-trifluoroacetamide (BSTFA) as a silylation
agent. The formed oxime and silyl derivates are shown for pinonic acid in figure 10.
ON
O SiOF
F
FF
F
OO
OH
1 PFBHA2 BSTFA
Figure 10. The derivatization method for carbonyls, alcohols, and acids.
The derivatized samples should be analyzed witin 12 h, in order to minimize the risk
of samples breaking down. We have observed some losses of sampled compounds
that have been stored in room temperature for more than 24 h.
- 19 -
8.3. Sampling in the presence of ozone
A potential problem in the sampling of VOCs in air is reactions between the
concentrated sampled compounds and reactive species in the air. Most studies have
focused on ozone, which is a reactive specie that is present in high concentrations
(182), but interferences by NO2 have also been reported (183). Ozone has been
shown to react with unsaturated compounds, which leads to an underestimation of the
concentration in the sample and artifact formation (182, 186, 187). Losses of 8-97%
have been reported for monoterpenes in the presence of 23-50 ppb ozone (172, 187,
188) and various artifacts have been presented (182, 189-191). Oxidation reactions
during sampling can be reduced or eliminated by selectively removing the oxidant
prior to the adsorbent. A number of different chemicals have been used to remove
ozone, e.g., potassium iodide, cotton, sodium carbonate, sodium sulphite, etc. Helmig
(182) presents most of these in his excellent review article.
In paper I we examined a number of these chemicals with regard to ozone removing
properties and recovery of some terpenoid compounds. We showed that most
chemicals investigated were capable of removing ambient levels of ozone (potassium
iodide, poly(1,4-phenylene sulfide) (PFS), manganese dioxide, and sodium sulphite).
Only potassium iodide, however, had high recoveries of the tested compounds, i.e., a
recovery of >95% for monoterpenes and some of their reaction products.
9. ANALYSIS Analysis of VOCs is conducted using a wide variety of analytical methods and
techniques (173, 175, 192, 193). All of the methods have advantages and
disadvantages and are more suitable for certain groups of compounds then others.
Two of these methods, ATD-GC-FID (papers I, II, IV) and GC-PCI-MS (paper III)
have been used in this thesis.
9.1. ATD-GC-FID
Automated thermal desorption (ATD) injector connected to a gas chromatograph
(GC) using a flame ionization detector (FID) is commonly used in the detection of
e.g., monoterpenes (178), and is also widely used in various other applications (173).
The sample is thermally desorbed from a solid adsorbent onto a cold trap, which then
is rapidly heated and the sample is injected on a GC column. The components in the
- 20 -
sample are separated on the column and detected by the electric current that is formed
when the carbons in the compounds are ionized in the hydrogen flame in the FID. All
carbons in the different compounds yield signals; hence the total amount of carbon
present at a specific moment is detected.
9.2. GC-PCI-MS
Gas chromatography (GC) using positive chemical ionization (PCI) mass
spectrometry (MS) provides a method to analyze a number of oxidation products that
are relevant in atmospheric chemistry and this method is used extensively (31, 150,
154, 194, 195 and paper III). PCI is a soft ionization technique that produces ions
with little excess energy, which leads to less fragmentation than a hard ionization
method (e.g., electron ionization) (196). This technique often yields the protonated
molecular ion ((M+H)+) as the base peak. PCI uses a reagent gas, usually methane
(paper III), isobutane or ammonia, which is ionized by a electron beam to produce
thermal electrons and reactant ions, as shown with methane in equation 15. Reactant
ions will collide with other methane molecules and form CH5+, which will protonate
the sample in an acid-base type of reaction (equation 16 and 17).
CH4 + e- → CH4.+ + 2e- (15)
CH4.+ + CH4 → CH5
+ + CH3. (16)
CH5+ + M → (M+H)+ + CH4 (17)
Some methane ions will fragment, however, and these fragments will also react with
methane and yield, e.g., C2H5+ and C3H5
+. Some of these will also protonate the
sample and yield M+29 and M+41 adducts, which facilitates the identification of the
molecular ion.
The formed ions are then separated by their mass to charge ratio in an electric or
magnetic field, detected and amplified (196).
10. VENTILATION SYSTEMS Ventilation systems in a building have two main objectives, to supply fresh air and to
remove polluted air. In domestic and commercial buildings humans and the building
material pollute the indoor air. A human emits 18 L/h CO2, 40 g/h water and various
- 21 -
odors, and the policy, introduced by Yaglou et al. (197) in the 1930's, has been to
have a flow of air that removes these effluents so that >80% of the occupants
consider the indoor air quality to be acceptable. Recently the building and building
materials have also been recognized as pollution sources, and since VOCs emitted by
the building materials have an odor threshold that is lower than the airway irritation
estimates (198), the air flow has to be adapted to remove those pollutants as well
(199). These goals can be achieved with increasingly complex ventilation systems.
The most basic ventilation is called natural ventilation and the air is transported in
and out of the building through windows, slits, poorly isolated walls, etc. Natural
ventilation has no additional systems that supplies or removes air but can be built
with specialized exhaust vaults, which generates a slight under-pressure in the
building that removes the air (figure 11). In these buildings the ventilation ducts are
normally on the exhaust side only as the supply air enters the building directly
through slits.
Mechanichal systems depend on fans to supply and remove the air and there are two
types, systems that only have exhaust fans and systems that have fans for both the
exhaust and supply air. In buildings with exhaust fans only the supply air enters
directly into the building through slits and the exhaust air is removed through
ventilation ducts (figure 11). In buildings with exhaust and supply fans the supply air
is transported through ventilations ducts to the different rooms in the building. The
exhaust air is then removed through a different set of ventilation ducts (figure 11).
Buildings with both an exhaust and supply fan need to be more or less air-proof in
order to maintain the equilibrated flow between the fans.
Figure 11. Different ventilation systems. Natural ventilation (left), exhaust fan only
(middle), exhaust and supply fans (right).
- 22 -
There is a number of additional functions that can be applied to the ventilation system
and a number of different technical solutions to the specific requirements of
architects, building owners, occupants, climate, etc. A heating or cooling system is
often added, to the supply air in buildings with both a supply and exhaust fan.
Different techniques are used. Some use a heating coil in the supply air and some use
a heat exchanger that transfers the heat from the exhaust air to the supply air; these
can also be combined with the heating coil, etc. Two types of heat exchangers were
used in this thesis (paper IV), a rotary and a cross flow. The basic principle behind a
heat exchanger is to transfer the heat from the exhaust air to the incoming supply air.
In a rotary heat exchangers this heat transfer is conducted with a rotor that slowly
rotates between the exhaust and supply air. The rotor has a large surface area and this
leads to a high efficiency (80-90%). In a cross flow heat exchanger the heat transfer is
conducted by a grid of thin parallel channels. The supply air is not exposed to the
exhaust air (unless there are minute cracks present) and the heat transfer occurs
through the channel walls. A cross flow heat exchanger has a moderate surface area
and is less efficient (50-60%). Cooling is also often integrated in the ventilation
system and a number of techniques exist that are often referred to as air conditioning.
Some buildings reuse the exhaust air after it has passed some filters and has been
added with various amounts of outdoor air. Other additional functions include air
humidifier, various filters (for particles and/or chemicals), vibration dampers, etc.
10.1. Chemical reactions in ventilation systems.
Chemical reactions in the atmosphere are governed by the presence and absence of
sunlight that determines the composition of VOCs and OH and NO3 radicals (67).
Chemical reactions in the atmosphere are also considered to occur almost exclusively
in the gas-phase even though some heterogeneous reactions have proven to be vital
(67). In a ventilation system these two differences, a high surface to volume ratio and
complete darkness, alter the outcome and reaction rates of the chemical reaction that
occur.
The lack of sunlight will stop the photo dissociation of formed products and also the
dissociation of NO2, which lead to a decreased formation of OH radicals and ozone.
Absence of sunlight will also stop the dissociation of any formed NO3 radicals, which
could lead to an increased overall reactivity (67) so the net result is hard to predict.
- 23 -
Galvanized sheet metal, the primary surface material in most ventilation ducts, has a
Zn coated surface that has "islands" of ZnO (200-202). ZnO provides active sites that
could dissociate ozone and form molecular oxygen (203), which would form OH
radicals and increase the overall reactivity of the system. Bulanin et al. (203)
suggested that the ozone acts as a Lewis base and forms complexes with weaker
Lewis acids, and decomposes on sites with stronger Lewis acids. Zn and/or aluminum
(e.g., surfaces in the heat exchangers) have been shown to produce different
adsorption complexes with ozone, which supports this theory (51, 204). Smith (205)
stated that Zn is the most common reducing agent used to produce aldehydes and
ketones in liquid phase ozonolysis. This clearly shows that the surfaces present are
likely to have a high reactivity towards the products formed from ozone reactions.
In paper IV we studied the reaction between three monoterpenes (α-pinene, ∆3-
carene, limonene) and ozone in an authentic ventilation system. The ventilation
system consisted of an interchangeable heat exchanger (two different heat exchangers
were used, a cross flow and a rotary), 75 m ventilation duct, gas-phase generation
equipment, ozone and NOx monitoring devices and filters, etc, as shown in figure 12.
Figure 12. The experimental set-up: Charcoal filter (A), ozone inlet (B), air inlet (C),
micro-syringe injector (D), mixing zone (E), monoterpene and ozone sampling (F, H,
I), heat exchanger (G), valves (V 1-3). Please note that this figure depicts a cross flow
heat exchanger.
We observed that the ventilation system had a profound impact on the ozonolysis of
all investigated monoterpenes. When compared to a theoretical mathematical
- 24 -
calculation, based on the rate constants of all significant reactions, all monoterpenes
reacted more than predicted. These increases were significant, as shown in table 3.
We showed in paper IV that the ozonolysis of the monoterpenes were affected by the
experimental settings like surface area, amount of water, level of ozone and
interactions between these.
Table 3. The calculated (FACSIMILE) and measured amounts of reacted monoterpene.
α-pinene ∆3-carene limonene
Mathematical Calculationsa 2.2% 1.0% 5.3% Paper IIb 2.7% 3.7% 9.3% Cross flow heat exchangerc 5.5% 6.0% 9.2% Rotary heat exchangerc 12.5% 12.9% 14.8%
a Calculated (FACSIMILE) for 20 ppb monoterpene, 75 ppb ozone, and 75 s. b Obtained from the MLR models at the experimental settings 20 ppb monoterpene, 75 ppb ozone, and 75 s. c The experimental settings were 20 ppb monoterpene, 75 ppb ozone, 28.3 m2 ventilation duct surface area, and 75 s (paper IV). We also showed that the rotary heat exchanger itself increased the amount reacted in
addition to increasing the amount reacted in the ventilation duct.
11. CONCLUSIONS AND FUTURE WORK The main observation of this thesis is that reaction products are formed in ventilation
systems. Despite the short reaction times and the ambient levels of ozone and
monoterpenes used in our experiments, we showed that a number of oxidation
products were formed (paper III) and that the reaction rate is significantly increased
in a ventilation system (paper IV). This formation is underestimated by theoretical
calculations and leads to high amounts of known irritants in the indoor air. The
oxidation products formed have been suggested to contribute to the occurrence of
SBS (4, 5), and have been shown to cause adverse effects on the respiratory system in
mice (39). We show in paper IV that theoretical calculations underestimate the
formation of these oxidation products 3-13 times, depending on ventilation system
and monoterpene. Different factors that affect the ozonolysis of monoterpenes in
ventilation systems were also studied. We showed that the surface area and type of
heat exchanger affected the reaction rate for all monoterpenes.
- 25 -
In paper I we show that a potassium iodide scrubber enables sampling in the presence
of ozone without loss of the sampled compounds and additional oxidation. This
scrubber was used in all papers included in this thesis and its use is recommended
when sampling monoterpenes and their oxidation products in an ozone rich
environment.
In papers II and III the effect of the experimental conditions on the initial steps in the
ozonolysis was investigated, and also how these conditions affect the composition of
formed products. We showed that water plays an important and complex role both in
the initial stage of ozonolysis of ∆3-carene and in the formation and composition of
products from the ozonolysis of α-pinene. The use of experimental design facilitated
the evaluation of the investigated reactions. In papers II and III the impact of the OH
radicals that were formed in the ozonolysis were also studied. We showed that the
formation of OH radicals could be studied using multiple linear regression models
and that the presence or absence of OH radicals had a profound impact on the
formation of many of the formed products. We also made an observation of the lack
of formed OH radicals in the ozonolysis of limonene and discussed probable causes
of this observation.
Regarding future work, it would be very interesting to elucidate the precise nature of
the interaction/catalytic effect of the surfaces in the ventilation system. The impact of
other factors, e.g., additional heating, presence of NO3 radicals, etc, would be really
interesting to include in an investigation.
It would also be very interesting to examine the limonene-ozone reaction in greater
depth, preferably in additional experimental set-ups, to be able to confirm and explain
or disregard our observation. Work needs to be done in order to elucidate the role of
water in the initial steps of ozonolysis and its interaction with the formed products.
Also much more work needs to be done in general in the field of indoor air chemistry
in order to minimize the discomfort experienced by many. I believe that an
epidemiological study that includes the measurement of oxidation products would be
able to correlate chemical compounds in the indoor air with the occurrence of SBS.
- 26 -
12. ACKNOWLEDGEMENTS Tanken här är att man ska tacka alla dom som hjälpt en att nå ända hit. En uppgift
som egentligen inte är svår utan snarare väldigt tacksam, men ni är ju så många och
jag har så mycket att tacka för. Omnämnandena kommer i en löst förvirrad
vetenskaplig ordning.
Jag börjar med mina handledare Barbro och Calle som visat mig hur man gör. Barbro
tack för stöd, tillgänglighet och alla kloka ord både om forskning och annat. Du har
hjälpt mig att hitta mitt sätt att undersöka saker och formulera mig på. Calle, tack för
alla intensiva diskussioner och din röntgenblick som gör att du hittar artiklar i mina
utkast. Kurt, tack för att jag hann lära känna och inspireras av dig. Jag skulle även
vilja tacka min biträdande reservhandledare och tillika rumskamrat, Linda. Tack för
din tillgänglighet (du hade ju i och för sig inte mycket val…), ditt tålamod och den
klarhet du tillfogade alla mina förvirrade utkast, ideer och manuskript. Tack också
Pär för alla tips och diskussioner, även om alla inte har handlat om
forskningsrelaterade spörsmål.
Jag skulle även vilja tacka alla på miljökemi. Om man går med ett leende till jobbet,
diskuterar jonkällor och retentionstider över kaffet, kastar Tenaxrör på ballonger på
lunchen och övar på att sjunga konstiga visor på kvällarna finns det mycket som tyder
på att man jobbar på en trevlig och kreativ arbetsplats. Tack för All Hjälp! Utan er
alla hade detta arbete varit betydligt tunnare och mina arbetsdagar betydligt tråkigare!
Tack Albert Crenshaw (LA-Write Now) för dina utmärkta språkgranskningar och
roliga diskussioner.
Jag skulle även vilja tacka Arbetslivsinstitutet, Civilingenjörsförbundet,
Kempestiftelserna, Knut och Alice Wallenbergstiftelsen och Ångpanne Föreningen
för olika grad av finansiellt stöd.
Mina kompisar, i exil och här i Umeå, jag vet var ni bor…
Tisdagsgänget (i dess absolut vidaste bemärkelse) utan vars hjälp och inflytande detta
arbete hade kunnat slutföras mycket tidigare. Tack för all visdom, kreativitet och
inlevelse som jag utsatts för och som jag aldrig kommer att bli av med. För att
- 27 -
missbruka Bruce's text "I learned more from a 7 h tuseday evening than I ever did in
school…"
Min släkt som nu är spridd över större delen av landet, jag tänker på er. Hoppas att vi
ses snart igen på födelsedagar, grillkvällar och gåsamiddagar.
Mamma och pappa, tack för att ni gjort mig till den jag är. Tack för allt stöd och all
livsglädje. Pappa, jag saknar dig.
Jag skulle även vilja tacka min fru, Hanna, tack för att du har stöttat mig och alltid
finns där innan jag ens vet att jag behöver det och sist och minst Didrik, tack för att
du finns.
13. REFERENCES
1. Gummere, R. M. In Ad Lucilium Epistolae Morales III. 1971. Heinemann, London.
2. Brimblecombe, P. The big smoke. 1987. Routledge, London. 3. Ramazzini, B. Diseases of workers. 1983. The Classics of Medicine Library,
Gryphon Editions, New York. 4. Weschler, C. J.; Shields, H. C. Potential reactions among indoor pollutants. Atmos.
Environ. 1997, 31, 3487-3495. 5. Wolkoff, P.; Clusen, P.; Jensen, B.; Nielsen, G.; Wilkins, C. Are we measuring the
relevant indoor pollutants? Indoor Air 1997, 7, 92-106. 6. Spengler, J. D.; Sexton, K. Indoor air pollution: A public health perspective.
Science 1983, 221, 9-17. 7. Smith, K. R. Biofuels, air pollution and health. A global review. 1987. Plenum
Press, New York. 8. WHO. Air quality guidelines. 1999. WHO, Geneva. 9. Bruce, N.; Perez-Padilla, R.; Albalak, R. Indoor air pollution in developing
countries: a major environmental and public health challenge for the new millenium. Bull. World. Health. Organ. 2000, 78, 1078-1092.
10. WHO. World health report 2002, reducing risks, promoting healthy life. 2002. WHO, Geneva.
11. Wells, C. Diseases of the maxillary sinus in antiquity. Med. Biol. Illus. 1977, 27, 173-178.
12. Stolwijk, J. A. Risk assessment of acute health and comfort effects of indoor air pollution. Ann. N. Y. Acad. Sci. 1992, 641, 56-62.
13. WHO. Indoor air pollutants: exposure and health effects. EURO Rep. Stud. 1983, 78, 1-42.
14. Jones, A. P. Asthma and domestic air quality. Soc. Sci. Med. 1998, 47, 755-764.
- 28 -
15. Horvath, E. P. Building-related illness and sick building syndrome: from the specific to the vague. Cleve. Clin. J. Med. 1997, 64, 303-309.
16. Zeliger, H. I. Toxic effects of chemical mixtures. Arch. Environ. Health. 2003, 58, 23-29.
17. WHO. Indoor air quality research. (Euro reports and studies No. 103) 1984. WHO, Copenhagen.
18. Mendell, M. J.; Smith, A. H. Consistent pattern of elevated symptoms in air.conditioned office buildings: A reanalysis of epidemiologic studies. Am. J. Public. Health. 1990, 80, 1193-1199.
19. Apter, A.; Bracker, A.; Hodgson, M.; Sidman, J.; Leung, W. -Y. Epidemiology of the sick building syndrome. J. Allergy. Clin. Immunol. 1994, 94, 277-288.
20. Jones, A. P. Indoor air quality and health. Atmos. Environ. 1999, 33, 4535-4564. 21. Mølhave, L.; Bach, B.; Pedersen, O. F. Human reactions to low concentrations of
volatile organic compounds. Environ. Int. 1986, 12, 167-175. 22. Brown, S. K.; Sim, M. R.; Abramson, M. J.; Gray, C. N. Concentrations of
Volatile Organic Compounds in indoor Air- A Review. Indoor Air 1994, 4, 123-134.
23. Pommer, L.; Fick, J.; Andersson, B.; Sundell, J.; Nilsson, C.; Sjöström, M.; Stenberg, B. Class separation of buildings with high and low prevalence of SBS by principal Component Analysis. Indoor Air 2003, In press.
24. Godish, T.; Spengler, D. Relationships between ventilation and indoor air quality; a review. Indoor Air 1996, 6, 135-145.
25. Seppänen, O. A.; Fisk, W. J.; Mendell, M. J. Association of ventilation rates and CO2 concentrations with health and other responses in commercial and institutional buildings. Indoor Air 1999, 9, 226-252.
26. Seppänen, O.; Fisk, W. J. Association of ventilation system type with SBS symptoms in office workers. Indoor Air 2002, 2, 98-112.
27. Wargocki, P.; Wyon, D. P.; Sundell, J.; Clausen, G.; Fanger, P. O. The effects of outdoor air supply rate in an office on perceived air quality, sick building syndrome (SBS) symptoms and productivity. Indoor Air 2000, 10, 222-236.
28. Menzies, R.; Tamblyn, R.; Farant, J. -P.; Hanley, J.; Nunes, F.; Tamblyn, R. The effect of varying levels of outdoor-air supply on the symptoms of Sick Building Syndrome. N. Engl. J. Med. 1993, 328, 821-827.
29. Atkinson, R. Atmospheric chemistry of VOCs and NOx. Atmos. Environ. 2000, 34, 2063-2101.
30. Hakola, H.; Arey, J.; Aschmann, S. M.; Atkinson, R. Product Formation from the Gas -Phase Reaction of OH Radicals and O3 with a series of Monoterpenes. J. Atmosph. Chem. 1994, 18, 75-102.
31. Yu, J.; Cocker III, D. R.; Griffin, R. J.; Flagan, R. C.; Seinfeld, J. H. Gas-phase ozone oxidation of monoterpenes: gaseous and particulate products. J. Atmosph. Chem. 1999, 34, 207-258.
32. Van den Bergh, V; Vanhees, I; De Boer, R.; Compernolle, F.; Vinckier, C. Identification of the oxidation products of the reaction between α-pinene an
- 29 -
hydroxyl radicals by gas and high-performance liquid chromatography with mass spectrometric detection. J. Chromatogr. A. 2000, 896, 135-148.
33. Went, F. W. Blue Hazes in the Atmosphere. Nature 1960, 187, 641-643. 34. Weschler, C. J.; Shields, H. C. Indoor ozone/terpene reactions as a source of
indoor particles. Atmos. Environ. 1999, 33, 2301-2312. 35. Koch, S.; Winterhalter, R.; Uherek, E.; Kolloff, A.; Neeb, P.; Moortgat, G. K.
Formation of new particles in the gas-phase ozonolysis of monoterpenes. Atmos. Environ. 2000, 34, 4031-4042.
36. Brunekreef, B.; Holgate, S. T. Air pollution and health. Lancet 2002, 360, 1233-1242.
37. Kane, L. E.; Alarie, Y. Evaluation of sensory irritation from acrolein-formaldehyde mixtures. Am. Ind. Hyg. Assoc. J. 1978, 39, 270-274.
38. Karlberg, A. -T.; Dooms-Goossens, A. Contact allergy to oxidized d-limonene among dermatitis patients. Contact. Dermatitis. 1997, 36, 201-206.
39. Rohr, A. C.; Wilkins, C. K.; Clausen, P. A.; Hammer, M.; Nielsen, G. D.; Wolkoff, P.; Spengler, J. D. Upper airway and pulmonary effects of oxidation products from (+)-α-pinene, d-limonene, and isoprene in BALB/c mice. Inhal. Toxicol. 2002, 14, 663-684.
40. Kreiss, K.; Gomaa, A.; Kullman, G.; Fedan, K.; Simoes, E. J.; Enright, P. L. Clinical bronchiolitis obliterans in workers at a microwave-popcorn plant. N. Engl. J. Med. 2002, 347, 330-338.
41. Matura, M.; Goossens, A.; Bordalo, O.; Garcia-Bravo, B.; Magnusson, K.; Wrangsjö, K.; Karlberg, A. -T. Oxidized citrus oil (R-limonene): A frequent skin sensitizer in Europe. J. Am. Acad. Dermatol. 2002, 47, 709-714.
42. WHO. IARC monographs on the evaluation of carcinogenic risks to humans, vol 62. Wood dust and formaldehyde. 1995. WHO, Lyon.
43. Schönbein, C. F. Beobachtungen über den bei der elektrolysation des wassers und dem ausströmen der gewöhnlichen electrizitat aus spitzen eich entwichelnden geruch. Poggendorff's Annalen der Physik 1840, 50, 616.
44. Odling, W. Manual of Chemistry, Descriptive and Theoretical, Part 1. 1861. Longman, Green, Longman, Roberts, London.
45. Brodie, R. C. An experimental inquiry on the action of electricity on gases. I On the action of electricity on oxygen. Phil. Trans. 1872, 162, 435-484.
46. Streng, A. G. Miscibility and Compatibility of Some Liquid and Solidified Gases at Low Temperature. J. Chem. Eng. Data. 1971, 16, 357-359.
47. Shand, W. J.; Spurr, R. A. The molecular structure of ozone. J. Am. Chem. Soc. 1943, 65, 179-181.
48. Glocker, G. Estimated bond energies in carbon, nitrogen, oxygen and hydrogen compounds. J. Chem. Phys. 1951, 19, 124-125.
49. Xie, D.; Guo, H.; Peterson, K. A. Accurate ab initio near-equilibrium potential energy and dipole moment functions of the ground electronic state of ozone. J. Chem. Phys. A. 2000, 112, 8378-8386.
- 30 -
50. Meinwald, J. Notiz zur anwendung der markownikoffschen regel auf den verlauf der ozonisierung. Chem. Ber. 1955, 88, 1889-1891.
51. Oyama, S. T. Chemical and catalytic properties of ozone. Catal. Rev. 2000, 42, 279-322.
52. Bailey, P. S. Ozonation in Chemistry. 1982. Academic Press, New York. 53. Cotton, F. A.; Wilkinson, G. Advanced Inorganic Chemistry. 1988. John Wiley &
Sons, New York. 54. Atkinson, R. Gas-Phase Tropospheric chemistry of volatile organic compounds:
1. Alkanes and Alkenes. J. Phys. Chem. Ref. Data. 1997, 26, 215-290. 55. Environmental Protection Agency. Air quality criteria for ozone and related
photochemical oxidants. (EPA/600/P-93/004aF). 1996. Environmental Protection Agency, Washington, DC.
56. Environmental Protection Agency. Air quality criteria for ozone and other photochemical oxidants. Vol. 1 (EPA-600/8-84-020aF) 1986. Environmental Protection Agency, Research Triangel Park.
57. Paz, C. Some consequences of ozone exposure on health. Arch. Med. Res. 1997, 28, 163-170.
58. Daniel, B. M. The toxicity of air pollution in experimental and humans, the role of oxidative stress. Toxicol. Lett. 1994, 72, 269-277.
59. Steinberg, J. J.; Gleeson, J. L.; Gil, D. The pathobiology of ozone-induced damage. Arch. Environ. Health. 1990, 45, 80-87.
60. Fuhrer, J.; Skärby, L.; Ashmore, M. R. Critical levels for ozone effects on vegetation in Europe. Environ. Pollut. 1997, 97, 91-106.
61. Grandjean, A.; Fuhrer, J. Growth and leaf senescence in spring wheat (Triticum aestivum) grown at different ozone concentrations in open-top field chambers. Physiol. Plant. 1989, 77, 389-394.
62. Danielsson, H.; Pihl-Karlsson, G.; Karlsson, P. E.; Pleijel, H. Ozone uptake modelling and flux-response relationships- an assessment of ozone-induced yield loss in spring wheat. Atmos. Environ. 2003, 37, 475-485.
63. Chappelka, A. H.; Samuelson, L. J. Ambient ozone effects on forest trees of the eastern United States: a review. New Phytol. 1998, 139, 91-108.
64. Matyssek, R.; Innes, J. L. Ozone-A risk factor for trees and forests in Europe? Water Air Soil Pollut. 1999, 116, 199-226.
65. Ashmore, M. R.; Thwaites, R. H.; Cousins, D. A.; Power, S. A.; Morton, A. J. Effects of ozone on calcareous grassland communities. Water Air Soil Pollut. 1995, 85, 1527-1532.
66. Chapman, S. A theory of upper atmospheric ozone. Mem. R. Meteorol. Soc. 1930, 3, 103-125.
67. Seinfeld, J. H.; Pandis, S. N. Atmopheric Chemistry and Physics. 1998. John Wiley & Sons, New York.
68. Volz, A.; Kley, D. Evaluation of the Montsouris series of ozone measurements in the nineteenth century. Nature 1988, 332, 240-242.
- 31 -
69. Oltmans, S. J.; Levy, H. I Surface ozone measurements from a global network. Atmos. Environ. 1994, 28, 9-24.
70. Janach, W. E. Surface ozone: trend details, seasonal variations, and interpretation. J. Geophys. Res. D. 1989, 94, 18289-18295.
71. Jiang, Y.; Yung, Y. L. Concentrations of tropospheric ozone for 1979 to 1992 over tropical pacific South America from TOMS data. Science 1996, 272, 714-716.
72. Weschler, C. J.; Shields, H. C.; Naik, D. Indoor ozone exposure. J. Air Waste Manag. Assoc. 1989, 39, 1562-1568.
73. Weschler, C. J.; Shields, H. C.; Nalk, D. Indoor chemistry involving O3, NO, and NO2 as evidenced by 14 months of measurements at a site in southern California. Environ. Sci. Technol. 1994, 28, 2120-2132.
74. Reiss, R.; Ryan, P. B.; Tibbetts, S. J.; Koutrakis, P. Measurement of organic acids, aldehydes, and ketones in residential environments and their relation to ozone. J. Air Waste Manag. Assoc. 1995, 811-822.
75. Weschler, C. J. Ozone in indoor environments: concentrations and chemistry. Indoor Air 2000, 4, 269-288.
76. Weschler, C. J.; Shields, H. C. The influence of ventilation on reactions among indoor pollutants: Modeling and experimental observations. Indoor Air 2000, 2, 92-100.
77. Mueller, F. X.; Loeb, L.; Mapes, W. H. Decomposition rates of ozone in living areas. Environ. Sci. Technol. 1973, 7, 342-346.
78. Shair, F. H.; Heitner, K. L. Theoretical model for relating indoor pollutant concentrations to those outside. Environ. Sci. Technol. 1974, 8, 444-451.
79. Moriske, H. -J.; Ebert, G.; Konieczny, L.; Menk, G.; Schöndube, M. Concentrations and decay rates of ozone in indoor air in dependence on building and surface materials. Toxicol. Lett. 1998, 96-97, 319-323.
80. Klen, J. C.; Clausen, P. A.; Weschler, C. J.; Wolkoff, P. Determination of ozone removal rates by selected building products using the FLEC emission cell. Environ. Sci. Technol. 2001, 35, 2548-2553.
81. Lerdau, M.; Guenther, A.; Monson, R. Plant production and emission of volatile organic compounds. Bioscience 1997, 47, 373-383.
82. Fuentes, J. D.; Lerdau, M.; Atkinson, R.; Baldocchi, D.; Bottenheim, J. W.; Ciccioli, P.; Lamb, B.; Geron, C.; Gu, L.; Guenther, A.; Sharkey, T. D.; Stockwell, W. Biogenic hydrocarbons in the atmospheric boundary layer: A review. B. Am. Meteorol. Soc. 2000, 81, 1537-1575.
83. Wolkoff, P.; Schneider, T.; Kildeso, J.; Degerth, R.; Jaroszewski, M.; Schunk, H. Risk in cleaning: chemical and physical exposure. Sci. Total Environ. 1998, 215, 135-156.
84. Langenheim, J. Higher plant terpenoids: a phytocentric overview of their ecological roles. J. Chem. Ecol. 1994, 20, 1223-1280.
85. Delfine, S.; Csiky, O.; Seufert, G.; Loreto, F. Fumigation with exogenous monoterpenes of a non-isoprenoid-emitting oak (Quercus suber):
- 32 -
monoterpene acquisition, translocation, and effect on the photosyntetic properties at high temperatures. New Phytol. 2000, 146, 27-36.
86. Peñuelas, J.; Lluisà, J. Linking photorespiration, monoterpenes and thermotolerance in Quercus. New Phytol. 2002, 155, 227-237.
87. Guenther, A.; Geron, C.; Pierce, T.; Lamb, B.; Harley, P.; Fall, R. Natural emissions of non-methane volatile organic compounds, carbon monoxide, and oxides of nitrogen from North America. Atmos. Environ. 2000, 34, 2205-2230.
88. Guenther, A.; Hewitt, C. N.; Erickson, D.; Fall, R.; Geron, C.; Graedel, T.; Harley, P.; Klinger, L.; Lerdau, M.; McKay, W. A.; Pierce, T.; Scholes, B.; Steinbrecher, R.; Tallamraju, R.; Taylor, J.; Zimmerman, P. A global model of natural volatile organic compounds emissions. J. Geophys. Res. D. 1995, 100, 8873-8892.
89. Janson, R. Monoterpene Concentrations in and Above a Forest of Scots Pine. J. Atmos. Chem. 1992, 14, 385-394.
90. Komenda, M.; Koppmann, R. Monoterpene emissions from Scots pine (Pinus sylvestris): Field studies of emission rate variabilities. J. Geophys. Res. D. 2002, 107, Art. no. 4161.
91. Dement, W.; Tyson, B.; Mooney, H. Mechanism of monoterpene volatilization in Salvia mellifera. Phytochemistry 1975, 14, 2555-2557.
92. Loreto, F.; Ciccioli, P.; Cecinato, A.; Bracaleoni, E.; Frattoni, M.; Tricoli, D. Influence of environmental factors and air composition on the emissions of α-pinenefrom Quercus ilex leaves. Plant. Physiol. 1996, 110, 267-275.
93. Peñuelas, J.; Lluisà, J. BVOCs: plant defense against climate warming? TRENDS Plant Sci. 2003, 8, 105-109.
94. Burton, B. T. Volatile organic compounds. Clin. Allergy Immunol. 1997, 9, 127-153.
95. Atkinson, R.; Carter, W. P. L. Kinetics and mechanisms of the gas-phase reactions of ozone with organic compounds under atmospheric conditions. Chem. Rev. 1984, 84, 437-470.
96. Horie, O.; Moortgat, G. K. Gas-phase ozonolysis of alkenes. Recent advances in mechanistic investigations. Acc. Chem. Res. 1998, 31, 387-396.
97. Yokouchi, Y.; Ambe, Y. Aerosols formed from the chemical reaction of monoterpenes and ozone. Atmos. Environ. 1985, 19, 1271-1276.
98. Kavouras, I G.; Mihalopoulos, N.; Stephanou, E. G. Formation of atmospheric particles from organic acids produced by forests. Nature 1998, 395, 683-686.
99. Jenkin, M. E.; Shallcross, D. E.; Harvey, J. N. Development and application of a possible mechanism for the generation of cis-pinic acid from the ozonolysis of α- and β-pinene. Atmos. Environ. 2000, 34, 2837-2850.
100. Niki, H.; Maker, P. D.; Savage, C. M.; Breitenbach, L. P.; Hurley, M. D. FTIR spectroscopic study of the mechanism for the gas-phase reaction between ozone and tetramethylene. J. Phys. Chem. 1987, 91, 941-946.
- 33 -
101. Trainer, M.; Williams, E. J.; Parrish, D. D.; Buhr, M. P.; Allwine, E. J.; Westberg, H. H.; Feshenfeld, F. C.; Liu, S. C. Models and observation of the impact of natural hydrocarbons on rural ozone. Nature 1987, 329, 705-707.
102. Atkinson, R.; Aschmann, S. M.; Arey, J.; Shorees, B. Formation of OH radicals in the gas-phase reactions of O3 with a series of terpenes. J. Geophys. Res. D. 1992, 97, 6065-6073.
103. Chew, A. A.; Atkinson, R. OH radical formation yields from the gas-phase reactions of O3 with alkenes and monoterpenes. J. Geophys. Res. D. 1996, 101, 28649-28653.
104. Gutbrod, R.; Chindler, R. N.; Kraka, E.; Cremer, D. Formation of OH radicals in the gas phase ozonolysis of alkenes: the unexpected role of carbonyl oxides. Chem. Phys. Lett. 1996, 252, 221-229.
105. Marston, G.; McGill, C. D.; Rickard, A. R. Hydroxyl-radical formation in the gas-phase ozonolysis of 2-methylbut-2-ene. Geophys. Res. Lett. 1998, 25, 2177-2180.
106. Donahue, N. M.; Kroll, J. H.; Anderson, J. G.; Demerjian, K. L. Direct observations of OH production from the ozonolysis of olefins. Geophys. Res. Lett. 1998, 25, 59-62.
107. Kroll, J. H.; Clarke, J. S.; Donahue, N. M.; Anderson, J. G.; Demerjian, K. L. Mechanism of HOx formation in the gas-phase ozone-alkene reaction. 1. Direct, pressure-dependent measurements of prompt OH yields. J. Phys. Chem. A. 2001, 105, 1554-1560.
108. Criegee, R.; Wenner, G. Die ozonisierung des 9,10-oktalins. Justus Liebigs Ann. Chem. 1949, 9, 564-574.
109. Criegee, R. Mechanism of ozonolysis. Angew. Chem. Int. Ed. Engl. 1975, 14, 745-752.
110. Martinez, R. I; Herron, J. T.; Huie, R. E. The mechanism of ozone-alkene reactions in the gas-phase. A mass spectrometric study of the reactions of eight linear and branched-chain alkenes. J. Am. Chem. Soc. 1981, 103, 3807-3820.
111. Grosjean, E.; Grosjean, D. Gas phase reaction of alkenes with ozone: Formation yields of primary carbonyls and biradicals. Environ. Sci. Technol. 1997, 31, 2421-2427.
112. Bach, R.; Owensby, A.; Andres, J.; Schlegel, H. Electronic structure and reactivity of dioxirane and carbonyl oxide. J. Am. Chem. Soc. 1992, 114, 7207-7217.
113. Anglada, J. M.; Bofill, J. M.; Olivella, S.; Solé, A. Unimolecular isomerizations and oxygen atom loss in formaldehyde and acetaldehyde carbonyl oxides. A theoretical investigation. J. Am. Chem. Soc. 1996, 118, 4636-4647.
114. Adam, W.; Curci, R.; Edwards, J. O. Dioxiranes: A new class of powerful oxidants. Acc. Chem. Res. 1989, 22, 205-211.
115. Chan, W. -T.; Hamilton, I P. Mechanisms for the ozonolysis of ethene and propene: Reliability of quantum chemical predictions. J. Chem. Phys. 2003, 118, 1688-1701.
- 34 -
116. Hatakeyama, S.; Akimoto, H. Reactions of the Criegee Intermediates in the gas phase. Res. Chem. Intermed. 1994, 20, 503-524.
117. Su, F.; Calvert, J. G.; Shaw, J. H. A FTIR spectroscopic study of the ozone-ethene reaction mechanism in O2-rich mixtures. J. Phys. Chem. 1980, 84, 239-246.
118. Niki, H.; Maker, P. D.; Savage, C. M.; Britenbach, L. P. A FTIR study of a transitory product in the gas-phase ozone-ethylene reaction. J. Phys. Chem. 1981, 85, 1024-1027.
119. Hatakeyama, S.; Kobayashi, H.; Akimoto, H. Gas-phase oxidation of SO2 ion the ozone-olefin reactions. J. Phys. Chem. 1984, 88, 4736-4739.
120. Paulson, S. E.; Seinfeld, J. H. Atmospheric photochemical oxidation of 1-octene: OH, O3, and O(3P) reactions. Environ. Sci. Technol. 1992, 26, 1165-1173.
121. Horie, O.; Neeb, P.; Moortgat, G. K. The reactions of the Criegee intermediate CH3CHOO in the gas-phase ozonolysis of 2-butene isomers. Int. J. Chem. Kinet. 1997, 29, 461-468.
122. Hasson, A. S.; Ho, A. W.; Kuwata, K. T.; Paulson, S. E. Production of stabilized Criegee intermediates and peroxides in the gas phase ozonolysis of alkenes 2. Assymetric and biogenic alkenes. J. Geophys. Res. D. 2001, 106, 34143-34153.
123. Kroll, J. H.; Sahay, S. R.; Anderson, J. G.; Demerjian, K. L.; Donahue, N. M. Mechanism of HOx formation in the gas-phase ozone-alkene reaction. 2. Prompt versus thermal dissociation of carbonyl oxides to form OH. J. Phys. Chem. A. 2001, 105, 4446-4457.
124. Olzmann, M.; Kraka, E.; Cremer, D.; Gutbrod, R.; Andersson, S. Energetics, kinetics, and product distributions of the reactions of ozone with ethene and 2,3-dimethyl-2-butene. J. Phys. Chem. A. 1997, 101, 9421-9429.
125. Fenske, J. D.; Hasson, A. S.; Ho, A. W.; Paulson, S. E. Measurement of absolute unimolecular and bimolecular rate constants for CH3CHOO generated by the trans-2-butene reaction with ozone in the gas-phase. J. Phys. Chem. A. 2000, 104, 9921-9932.
126. Herron, J. T.; Martinez, R. I; Huie, R. E. Kinetics and energetics of the Criegee intermediate in the gas-phase. I. The Criegee intermediate in ozone-alkene reactions. Int. J. Chem. Kinet. 1982, 14, 201-224.
127. Hasson, A. S.; Orzechowska, G.; Paulson, S. E. Production of stabilized Criegee intermediates and peroxides in the gas phase ozonolysis of alkenes 1. Ethene, trans-2-butene, and 2,3-dimethyl-2-butene. J. Geophys. Res. D. 2001, 106, 34131-34142.
128. Ryzhkov, A. B.; Ariya, P. A. A theoretical study of the reactions of carbonyl oxide with water in atmosphere: the role of water dimer. Chem. Phys. Lett. 2003, 367, 423-429.
129. Schäfer, C.; Horie, O.; Crowley, J. N.; Moorgat, G. K. Is the hydroxyl radical formed in the gas-phase ozonolysis of alkenes? Geophys. Res. Lett. 1997, 24, 1611-1614.
- 35 -
130. Crehuet, R.; Anglada, J. M.; Cremer, D.; Bofill, J. M. Reaction modes of carbonyl oxide, dioxirane, and methylenebis(oxy) with ethylene: A new reaction mechanism. J. Phys. Chem. A. 2002, 106, 3917-3929.
131. Aplincourt, P.; Ruiz-López, M. F. Theoretical study of formic acid anhydride formation from carbonyl oxide in the atmosphere. J. Phys. Chem. A. 2000, 104, 380-388.
132. Johnson, D.; Lewin, A. G.; Marston, G. The effect of Criegee-Intermediate Scavengers on the OH Yield from the Reaction of Ozone with 2-methylbut-2-ene. J. Phys. Chem. A. 2001, 105, 2933-2935.
133. Crehuet, R.; Anglada, J. M.; Bofill, J. M. Tropospheric formation of Hydroxymethyl Hydroperoxide, Formic Acid, H2O2, and OH from carbonyl oxide in the presence of water vapor: A Theoretical study of the reaction mechanism. Chem.-Eur. J. 2001, 7, 2227-2235.
134. Becker, K. H.; Brockmann, K. J.; Bechara, J. Production of hydrogen peroxide in forest air by reaction of ozone with terpenes. Nature 1990, 346, 256-258.
135. Neeb, P.; Sauer, F.; Horie, O.; Moortgat, G. K. Formation of hydroxymethyl hydroperoxide and formic acid in alkene ozonolysis in the presence of water vapour. Atmos. Environ. 1997, 31, 1417-1423.
136. Alvarado, A.; Tuazon, E. C.; Aschmann, S. M.; Atkinson, R.; Arey, J. Products of the gas-phase reactions of O(3P) atoms and O3 with α-pinene and 1,2-dimethyl-1-cyclohexene. J. Geophys. Res. D. 1998, 103, 25541-25551.
137. Baker, J.; Aschmann, S. M.; Arey, J.; Atkinson, R. Reactions of stabilized Criegee Intermediates from the gas-phase reactions of O3 with selected terpenes. Int. J. Chem. Kinet. 2001, 34, 73-85.
138. Lee, M.; Heikes, B. G.; O'Sullivan, D. W. Hydrogen peroxide and organic hydroperoxide in the troposphere: a review. Atmos. Environ. 2000, 34, 3475-3494.
139. Sauer, F.; Schäfer, C.; Neeb, P.; Horie, O.; Moortgat, G. K. Formation of hydrogen peroxide in the ozonolysis of isoprene and simple alkenes under humid conditions. Atmos. Environ. 1999, 33, 229-241.
140. Winterhalter, R.; Neeb, P.; Grossmann, D.; Kolloff, A.; Horie, O.; Moortgat, G. Products and mechanism of the gas phase reaction of ozone with β-pinene. J. Atmos. Chem. 2000, 35, 165-197.
141. Johnson, D.; Rickard, A. R.; McGill, C. D.; Marston, G. The influence of orbital asymetry on the kinetics of the gas-phase reactions of ozone with unsaturated compounds. Phys. Chem. Chem. Phys. 2000, 2, 323-328.
142. Cremer, E.; Kraka, E.; Szalay, P. G. Decomposition modes of dioxirane, methyldioxirane and dimethyldioxirane- A CCSD(T), MR-AQCC and DFT investigation. Chem. Phys. Lett. 1998, 292, 97-109.
143. Atkinson, R.; Arey, J. Atmospheric chemistry of biogenic organic compounds. Acc. Chem. Res. 1998, 31, 574-583.
144. Rickard, A. R.; Johnson, D.; McGill, C. D.; Marston, G. OH Yields in the gas-phase reactions of ozone with alkenes. J. Phys. Chem. A. 1999, 103, 7656-7664.
- 36 -
145. Pfeiffer, T.; Forberich, O.; Comes, F. J. Tropospheric OH formation by ozonolysis of terpenes. Chem. Phys. Lett. 1998, 298, 351-358.
146. Aschmann, S. M.; Arey, J.; Atkinson, R. OH radical formation from the gas-phase reactions of ozone with a series of terpenes. Atmos. Environ. 2002, 36, 4347-4355.
147. Atkinson, R.; Arey, J. Gas-phase tropospheric chemistry of biogenic volatile organic compounds: a review. Atmos. Environ. 2003, in press.
148. Hatakeyama, S.; Izumi, K.; Fukuyama, T.; Akimoto, H. Reactions of ozone with α-pinene and β-pinene in air: Yields of gaseous and particulate products. J. Geophys. Res. D. 1989, 94, 13013-13024.
149. Grosjean, D.; Williams, E. L. I; Seinfeld, J. H. Atmospheric oxidation of selected terpenes and related carbonyls: Gas-phase carbonyl products. Environ. Sci. Technol. 1992, 26, 1526-1533.
150. Yu, J.; Flagan, R. C.; Seinfeld, J. H. Identification of products containing -COOH, -OH, and -CO in atmospheric oxidation of hydrocarbons. Environ. Sci. Technol. 1998, 32, 2357-2370.
151. Glasius, M.; Duane, M.; Larsen, B. R. Determination of polar oxidation products in aerosols by liquid chromatography-ion trap mass spectrometry. J. Chromatogr. A. 1999, 833, 121-135.
152. Jang, M.; Kamens, R. M. Newly characterized products and composition of secondary aerosols from the reaction of α-pinene with ozone. Atmos. Environ. 1999, 33, 459-474.
153. Warscheid, B.; Hoffmann, T. On-Line measurements of α-pinene ozonolysis products using an atmospheric pressure chemical ionisation ion-trap mass spectrometer. Atmos. Environ. 2001, 35, 2927-2940.
154. Jaoui, M.; Kamens, R. M. Mass balance of gaseous and particulate products analysis from α-pinene/NOx/air in the presence of natural sunlight. J. Geophys. Res. D. 2001, 106, 12541-12558.
155. Jaoui, M.; Kamens, R. M. Gaseous and particulate oxidation products analysis of a mixture of α-pinene + β-pinene/O3/air in the absence of light and α-pinene + β-pinene/NOx/air in the presence of natural sunlight. J. Atmos. Chem. 2003, 44, 259-297.
156. Berndt, T.; Böge, O.; Stratmann, F. Gas-phase ozonolysis of α-pinene: gaseous products and particle formation. Atmos. Environ. 2003, 37, 3933-3945.
157. Orlando, J. J.; Nozière, B.; Tyndall, G. S.; Orzechowska, G. E.; Paulson, S. E. Product studies of the OH- and ozone-initiated oxidation of some monoterpenes. J. Geophys. Res. D. 2000, 105, 11561-11572.
158. Reisell, A.; Harry, C.; Aschmann, S. M.; Atkinson, R.; Arey, J. Formation of acetone from the OH radical- and O3-initiated reactions of a series of monoterpenes. J. Geophys. Res. D. 1999, 104, 13869-13879.
159. Aschmann, S. M.; Reissell, A.; Atkinson, R.; Arey, J. Products of the gas phase reactions of the OH radical with α- and β-pinene in the presence of NO. J. Geophys. Res. D. 1998, 103, 25553-25561.
- 37 -
160. Larsen, B. R.; Bella, D. D.; Glasius, M.; Winterhalter, R.; Jensen, N. R.; Hjorth, J. Gas-phase OH oxidation of monoterpenes: Gaseous and particulate products. J. Atmos. Chem. 2001, 38, 231-276.
161. Aschmann, S. M.; Atkinson, R.; Arey, J. Products of reaction of OH radicals with α-pinene. J. Geophys. Res. D. 2002, 107, Art. no. 4191.
162. Aschmann, S. M.; Arey, J.; Atkinson, R. Formation of beta-hydroxycarbonyls from the OH radical-initiated reactions of selected terpenes. Environ. Sci. Technol. 2000, 34, 1702-1706.
163. Hallquist, M.; Wängberg, I; Ljungström,E. Atmospheric fate of carbonyl oxidation products originating from α-pinen and ∆3-carene: Determination of rate of reaction with OH and NO3 radicals, UV absorption cross sections and vapour pressures. Environ. Sci. Technol. 1997, 31, 3166-3172.
164. Alavarado, A.; Arey, J.; Atkinson, R. Kinetics of the gas-phase reactions of OH and NO3 radicals and O3 with the monoterpene reaction products pinonaldehyde, caronaldehyde and sabinaketone. J. Atmos. Chem. 1998, 34, 281-297.
165. Noziere, B.; Barnes, I; Becker, K. . -H. Product study and mechanisms of the reactions of α-pinene and of pinonaldehyde with OH radicals. J. Geophys. Res. D. 1999, 104, 23645-23656.
166. Noziere, B.; Spittler, M.; Ruppert, L.; Barnes, I; Becker, K. H.; Pons, M.; Wirtz, K. Kinetics of the reactions of pinonaldehyde with OH radicals and with Cl atoms. Int. J. Chem. Kinet. 1999, 31, 291-301.
167. Dibble, T. S. Reactions of the alkoxy radicals formed following OH-addition to α-pinene and β-pinene. C-C bond scission reactions. J. Am. Chem. Soc. 2001, 123, 4228-4234.
168. Vereecken, L.; Peeters, J. Enhanced H-atom abstraction from pinon aldehyde, pinonic acid, pinic acid, and related compounds: theoretical study of C-H bond strenghts. Phys. Chem. Chem. Phys. 2002, 4, 467-472.
169. Box, G. E. P.; Hunter, W. G.; Hunter, J. S. Statistics for experimenters: An introduction to design, data analysis, and model building. 1978. John Wiley & Sons, New York.
170. Malleson, A. M.; Kellet, H. M.; Myhill, R. G.; Sweetenham, W. P. Facsimile user guide. 1990. United Kingdom Atomic Energy Authority, Industrial Research and Technical Service, Harwell lab. Oxfordshire.
171. Camel, V; Caude, M. Trace enrichment methods for the determination of organic pollutants in ambient air. J. Chromatogr. A. 1995, 710, 3-19.
172. Hoffmann, T. Adsorptive preconcentration technique including oxidant scavening for the measurement of reactive natural hydrocarbons in ambient air. Fresenius J. Anal. Chem. 1995, 351, 41-47.
173. Helmig, D. Air analysis by gas chromatography. J. Chromatogr. A. 1999, 843, 129-146.
174. Harper, M. Sorbent trapping of volatile organic compounds from air. J. Chromatogr. A. 2000, 885, 129-151.
- 38 -
175. Aragón, P.; Atienza, J.; Climent, M. D. Analysis of organic compounds in air: A review. Crit. Rev. Anal. Chem. 2000, 30, 121-151.
176. Dettmer, K.; Engewald, W. Adsorbent materials commonly used in air analysis for adsorptive enrichment and thermal desorption of volatile organic compounds. Anal. Bioanal. Chem. 2002, 373, 490-500.
177. Rothweiler, H.; Wäger, P. A.; Schlatter, C. Comparison of Tenax TA and carbotrap for sampling and analysis of volatile organic compounds in air. Atmos. Environ. 1991, 25B, 231-235.
178. Larsen, B.; Bomboi-Mingarro, T.; Brancaleoni, E.; Calogirou, A.; Cecinato, A.; Coeur, C.; Chatzianestis, I; Duane, M.; Frattoni, M.; Fugit, J. -L.; Hansen, U.; Jacob, V; Mimikos, N.; Hoffmann, T.; Owen, S.; Perez-Pastor, R.; Reichmann, A.; Seufert, G.; Staudt, M. Sampling and analysis of terpenes in air. An inter laboratory study. Atmos. Environ. 1997, 31, 35-49.
179. Poole, C. F.; Poole, S. K.; Seibert, D. S.; Chapman, C. M. Determination of kinetics and retention properties of cartridge and disk devices for solid-phase extraction. J. Chromatogr. B. 1997, 689, 245-259.
180. Comes, P.; Gonzalez-Flescha, N.; Ménard, T.; Grimalt, J. O. Langmuir-derived equations for the predictions of solid adsorbent breakthrough volumes of volatile organic compounds in atmospheric emission effluents. Anal. Chem. 1993, 65, 1048-1053.
181. Foley, P.; Gonzalez-Flescha, N.; Zdanevitch, I; Corish, J. An investigation of the adsorption of C5-C12 hydrocarbons in the ppmv and ppbv ranges on carbotrap B. Environ. Sci. Technol. 2001, 35, 1671-1679.
182. Helmig, D. Ozone removal techniques in the sampling of atmospheric volatile organic trace gases. Atmos. Environ. 1997, 31, 3635-3651.
183. Pommer, L.; Fick, J.; Andersson, B.; Nilsson, C. Development of a NO2 scrubber for accurate sampling of ambient levels of terpenes. Atmos. Environ. 2002, 36, 1443-1452.
184. Melcher, R. G.; Peters, T. L.; Emmel, H. W. Sampling and sample preparation of environmental material. Top. Curr. Chem. 1986, 134, 59-123.
185. Poole, S. K.; Dean, T. A.; Oudsema, J. W.; Poole, C. F. Sample preparation for chromatographic separations: an overview. Anal. Chim. Acta. 1990, 236, 3-42.
186. Pellizzari, E.; Demian, B.; Krost, K. Sampling of organic compounds in the presence of reactive inorganic gases with Tenax GC. Anal. Chem. 1984, 56, 793-798.
187. Juttner, F. A cryotrap technique for the quantification of monoterpenes in humid and ozone-rich forest air. J. Chromatogr. A. 1988, 442, 157-163.
188. Peters, R. J. B.; Duivenbode, J. A. D. V R.; Duyzer, J. H.; Verhagen, H. L. M. The determination of terpenes in forest air. Atmos. Environ. 1994, 28, 2413-2419.
189. Helmig, D.; Arey, J. Organic chemicals in the air at Whitaker's Forest/Sierra Nevada mountains, California. Sci. Total Environ. 1992, 112, 233-250.
190. Calogirou, A.; Larsen, B. R.; Brussol, C.; Duane, M.; Kotzias, D. Decomposition of terpenes by ozone during sampling on tenax. Anal. Chem. 1996, 68, 1499-1506.
- 39 -
191. Bates, M. S.; Gonzalez-Flesca, N.; Sokhi, R.; Cocheo, V Atmospheric volatile organic compound monitoring. Ozone induced artefact formation. Environ. Monit. Assess. 2000, 65, 89-97.
192. Cao, X. L.; Hewitt, C. N. Detection methods for the analysis of biogenic nonmethane hydrocarbons in air. J. Chromatogr. A. 1995, 710, 39-50.
193. Dewulf, J.; Van Langenhove, H. Analysis of volatile organic compounds using gas chromatography. Trends Analyt. Chem. 2002, 21, 637-646.
194. Jang, M.; Kamens, R. M. Newly characterized products and composition of secondary aerosols from the reaction of α-pinene with ozone. Atmos. Environ. 1999, 33, 459-474.
195. Jaoui, M.; Leungsakul, S.; Kamens, R. M. Gas and particle products distribution from the reaction of β-caryophyllene with ozone. J. Atmos. Chem. 2003, 45, 261-287.
196. De Hoffmann, E.; Stroobant, V. Mass spectrometry. Principles and applications. Second edition. 2002. John Wiley & Sons. New York.
197. Yaglou, C. P.; Riley, E. C.; Coggins, D. I. Ventilation requirements. ASHRAE trans. 1936, 42, 133-162.
198. Wolkoff, P. How to measure and evaluate volatile organic compound emissions from building products. A perspective. Sci. Total. Environ. 1999, 227, 197-213.
199. Fanger, P. O. Discomfort caused by odorants and irritants in the air. Indoor Air 1998, Suppl. 4, 81-86.
200. Marder, A. R. The metallurgy of zinc coated steel. Prog. Mater. Sci. 2000, 45, 191-271.
201. Pérez, C.; Collazo, A.; Izquierdo, M.; Merino, P.; Nóvoa, X. R. Comparative study between galvanized steel and three duplex systems submitted to a weathering cyclic test. Corros. Sci. 2002, 44, 481-500.
202. Kazinczy, B.; Kótai, L.; Sajó, I E.; Holly, S.; Lázár, K.; Jakab, E.; Gács, I; Szentmihályi, K. Phase relations and heat-induced chemical processess in sludges of Hot-Dip galvanization. Indust. Eng. Chem. Res. 2002, 41, 720-725.
203. Bulanin, K. M.; Lavalley, J. C.; Tsyganenko, A. A. IR spectra of adsorbed ozone. Colloid. Surface. A. 1995, 101, 153-158.
204. Alebic-Juretic, A.; Cvitaš, T.; Klasinc, L. Kinetics of heterogenous ozone reactions. Chemosphere 2000, 41, 667-670.
205. Smith, M. B. Organic synthesis. 1994. Mcgraw-Hill, New York.