Indoor and outdoor air concentrations as well as personal exposure concentrations of volatile organic compounds (VOCs) have been measured during 2003–2008 in public buildings, schools, kindergartens ...and private homes in eleven cities over Europe covering geographic areas in north, central and south Europe during different seasons within the frame of the AIRMEX (European Indoor Air Monitoring and Exposure assessment) study. A database is presented containing the results for 23 VOCs based upon approximately 1000 samples taken from 182 different working environments (offices, classrooms, waiting halls) in public buildings, schools and kindergartens, from 103 private homeplaces and from adult volunteers (148 samples). The statistical analysis of the data demonstrated that sources in the indoor environment are prevailing for most of the investigated VOCs with indoor/outdoor (I/O) concentration ratios following the order: hexanal ≈
d-limonene ≫ formaldehyde > acetone > 1-butoxy-2-propanol > acetaldehyde > propanal > 1-butanol > n-undecane > methylcyclohexane > n-dodecane. For aromatic hydrocarbons the main impact was shown to be penetration from outdoor air as indicated by I/O ratios near one and is characterised by significantly higher indoor as well as outdoor concentrations in the south of Europe with respect to the north. For the terpenes, the lowest indoor concentrations were measured during the warm season, which may be explained by higher ventilation rates and reactions with ozone penetrated from outdoor air.
► Prioritized pollutants measurement campaigns in 11 European cities. ► Measurement campaigns at different periods. ► Statistical analysis to investigate dependency on position and season. ► Exhaustive database of concentrations of indoor pollutants in 11 European cities.
A series of smog chamber experiments have been conducted in which five cyclic monoterpenes were oxidized by ozone. The evolved secondary aerosol was analyzed by GC-MS and HPLC-MS for nonvolatile ...polar oxidation products with emphasis on the identification of carboxylic acids. Three classes of compounds were determined at concentration levels corresponding to low percentage molar yields: i.e. dicarboxylic acids, oxocarboxylic acids, and hydroxyketocarboxylic acids. Carboxylic acids are highly polar and have lower vapor pressures than their corresponding aldehydes and may thus play an important role in secondary organic aerosol formation processes. The most abundant carboxylic acids were the following: cis-pinic acid AB1 (cis-3-carboxy-2,2-dimethylcyclobutylethanoic acid) from α- and β-pinene; cis-pinonic acid A3 (cis-3-acetyl-2,2-dimethylcyclobutylethanoic acid) and cis-10-hydroxypinonic acid AB6 (cis-2,2-dimethyl-3-hydroxyacetylcyclobutylethanoic acid) from α-pinene and β-pinene; cis-3-caric acid C1 (cis-2,2-dimethyl-1,3-cyclopropyldiethanoic acid), cis-3-caronic acid C3 (2,2-dimethyl-3-(2-oxopropyl)cyclopropanylethanoic acid), and cis-10-hydroxy-3-caronic acid C6 (cis-2,2-dimethyl-3-(hydroxy-2-oxopropyl)cyclopropanylethanoic acid) from 3-carene; cis-sabinic acid S1 (cis-2-carboxy-1-isopropylcyclopropylethanoic acid) from sabinene; limonic acid L1 (3-isopropenylhexanedioic acid), limononic acid L3 (3-isopropenyl-6-oxo-heptanoic acid), 7-hydroxylimononic acid L6 (3-isopropenyl-7-hydroxy-6-oxoheptanoic acid), and 7-hydroxylimononic acid L6‘ (7-hydroxy-3-isopropenyl-6-oxoheptanoic acid) from limonene.
The present investigation, carried out as a case study in a typical major city situated in a European coal combustion region (Krakow, Poland), aims at quantifying the impact on the urban air quality ...of residential heating by coal combustion in comparison with other potential pollution sources such as power plants, industry, and traffic. Emissions were measured for 20 major sources, including small stoves and boilers, and the particulate matter (PM) was analyzed for 52 individual compounds together with outdoor and indoor PM10 collected during typical winter pollution episodes. The data were analyzed using chemical mass balance modeling (CMB) and constrained positive matrix factorization (CMF) yielding source apportionments for PM10, B(a)P, and other regulated air pollutants namely Cd, Ni, As, and Pb. The results are potentially very useful for planning abatement strategies in all areas of the world, where coal combustion in small appliances is significant. During the studied pollution episodes in Krakow, European air quality limits were exceeded with up to a factor 8 for PM10 and up to a factor 200 for B(a)P. The levels of these air pollutants were accompanied by high concentrations of azaarenes, known markers for inefficient coal combustion. The major culprit for the extreme pollution levels was demonstrated to be residential heating by coal combustion in small stoves and boilers (>50% for PM10 and >90% B(a)P), whereas road transport (<10% for PM10 and <3% for B(a)P), and industry (4−15% for PM10 and <6% for B(a)P) played a lesser role. The indoor PM10 and B(a)P concentrations were at high levels similar to those of outdoor concentrations and were found to have the same sources as outdoors. The inorganic secondary aerosol component of PM10 amounted to around 30%, which for a large part may be attributed to the industrial emission of the precursors SO2 and NO x .
Smog chamber experiments have beenconducted in which cyclic monoterpenes were oxidisedin the gas phase by OH. The evolved secondary organicaerosol (SOA) was analysed by LC-MS^sup n^ and thegas-phase ...products were analysed by FT-IR. Theconcentrations of the identified compoundscorresponded to carbon mass balances in the range of40%-90%. The identified compounds in the particularphase corresponded to 0.5%-4.2% of the reactedcarbon. The most abundant compounds in SOA fromterpenes with an endocyclic C=C double bond wereC^sub 10^-keto-aldehydes, C^sub 10^-keto-carboxylicacids, C^sub 10^-hydroxy-keto-carboxylic acids, andC^sub 10^-hydroxy-keto-aldehydes (pinonaldehyde,pinonic acid, hydroxy-pinonic acid isomers, andhydroxy-pinonaldehyde isomers from α-pinene;3-caronaldehyde, 3-caronic acid, hydroxy-3-caronicacid isomers, and hydroxy-3-caronaldehyde isomers from3-carene). The most abundant compounds in SOA fromterpenes with an exocyclic C=C double bond wereC^sub 9^-ketones, C^sub 9^-dicarboxylic acids, andC^sub 10^-hydroxy-keto-carboxylic acids (nopinone,pinic acid, and hydroxy-pinonic acid isomers fromβ-pinene; sabinaketone, sabinic acid andhydroxy-sabinonic acid isomers from sabinene).Decarboxylated analogues of most of the compounds werepresent in SOA in minor concentrations, such asC^sub 9^-keto-carboxylic acids (norpinonic acid,nor-3-caronic acid) and C^sub 8^-dicarboxylic acids(norpinic acid, nor-3-caric acid, norsabinic acid). InSOA from limonene, which contains an endocyclic aswell as an exocyclic C=C double bond, the mostabundant compounds were a C^sub 10^-keto-aldehyde andits oxo-derivative (limononaldehyde and keto-limononaldehyde) together with hydroxy-derivatives of aC^sub 10^-keto-carboxylic acid (isomers ofhydroxy-limononic acid). Also aC^sub 10^-keto-carboxylic acid (limononic acid) waspresent together with minor concentrations of aC^sub 9^-dicarboxylic acids (limonic acid), itsoxo-derivative (keto-limonic acid), and itsdecarboxylated analogue (norlimonic acid). Mechanisticpathways for the formation of these products, some ofwhich are identified here for the first time, areproposed.PUBLICATION ABSTRACT
One of the major technological challenges for the transport sector is to cut emissions of particulate matter (PM) and nitrogen oxides (NO x ) simultaneously from diesel vehicles to meet future ...emission standards and to reduce their contribution to the pollution of ambient air. Installation of particle filters in all existing diesel vehicles (for new vehicles, the feasibility is proven) is an efficient but expensive and complicated solution; thus other short-term alternatives have been proposed. It is well known that water/diesel (W/D) emulsions with up to 20% water can reduce PM and NO x emissions in heavy-duty (HD) engines. The amount of water that can be used in emulsions for the technically more susceptible light-duty (LD) vehicles is much lower, due to risks of impairing engine performance and durability. The present study investigates the potential emission reductions of an experimental 6% W/D emulsion with EURO-3 LD diesel vehicles in comparison to a commercial 12% W/D emulsion with a EURO-3 HD engine and to a Cerium-based combustion improver additive. For PM, the emulsions reduced the emissions with −32% for LD vehicles (mass/km) and −59% for the HD engine (mass/kWh). However, NO x emissions remained unchanged, and emissions of other pollutants were actually increased for the LD vehicles with +26% for hydrocarbons (HC), +18% for CO, and +25% for PM-associated benzoapyrene toxicity equivalents (TEQ). In contrast, CO (−32%), TEQ (−14%), and NO x (−6%) were reduced by the emulsion for the HD engine, and only hydrocarbons were slightly increased (+16%). Whereas the Cerium-based additive was inefficient in the HD engine for all emissions except for TEQ (−39%), it markedly reduced all emissions for the LD vehicles (PM −13%, CO −18%, HC −26%, TEQ −25%) except for NO x , which remained unchanged. The presented data indicate a strong potential for reductions in PM emissions from current diesel engines by optimizing the fuel composition.
A new method for the determination of polar terpene oxidation products in secondary aerosols is described. It is based on collection of particles on PTFE filters and extraction with dichloromethane ...followed by analysis with liquid chromatography–ion-trap mass spectrometry (MS
n
) using pneumatically assisted electrospray ionisation (ESI) and atmospheric pressure chemical ionisation (APCI) with the ion-trap operated in the product scan mode. Separations were achieved on a C
18 reversed-phase column with methanol–water (0.1% acetic acid) as eluent. The method has a high sensitivity (instrument detection limit 0.7–7 pg/μl at
S/N=3) and precision (5–10%) and a good linearity. Acidic oxidation products produce strong signals with ESI. They appear as negative quasimolecular ions M−H
−, acetate adducts M+CH
3COO
− and molecular clusters 2M−H
−. In the MS
2 mode these acids show strong signals from neutral loss of CO
2: M−H−CO
2
−, and/or weaker signals from loss of H
2O: M−H−H
2O
−, M−H−H
2O−CO
2
−. Mass spectra were recorded by APCI for a number of oxygenated terpenoid standards containing keto groups, hydroxy groups, aldehyde groups, or epoxy groups. These compounds give intense signals as their positive quasimolecular ions M+H
+, methanol adducts M+H+CH
3OH
+ and fragments from loss of water, such as M+H−H
2O
+, M+H+CH
3OH−H
2O
+ and M+H−2H
2O
+. By MS
2 and MS
3 neutral loss of H
2O and 2H
2O is observed. The method has been tested in analysis of aerosol from O
3–α-pinene and O
3–myrtenol and has been proved to compare well with classical methods based on derivatisation and gas chromatography mass spectrometry. Three new compounds, tentatively identified in aerosol are reported here for the first time: 10-hydroxypinonic acid, 9-hydroxynorpinonic acid and pinalic 4-acid.
Using an in vitro fermentation system, human faecal flora metabolism of quercetin-3-rhamnoglucoside (rutin), hesperetin-7-rhamnoglucoside (hesperidin), naringenin-7-rhamnoglucoside (naringin) and ...their respective aglycones quercetin, hesperetin, and naringenin were investigated. Substrate degradation and metabolite formation were determined by high-performance liquid chromatography and mass spectrometry. The three flavonoid glycosides were completely metabolized within the 72-h fermentation period, but differences in the degradation patterns were observed. Rutin degradation did not lead to detectable levels of free quercetin, whereas the aglycones of hesperidin and naringin were produced. Considerable amounts of hesperetin were accumulated in the hesperidin substrate within the first 8 fermentation hours. The fermentation of naringin however, led to a linear increase of the aglycone over the whole incubation period. It is concluded from these observations that the flavonoid structure and position of the glycosidic linkage affects the degradation pattern of flavonoid rhamnoglucosides. The metabolites were determined to be phenolic compounds such as hydroxy- and methoxyphenyl -acetic and -propionic acids and an aldehyde.
A critical examination of data, assumptions and statistical approaches for previously published QSARs for the octanol-water and soil-water partition coefficients (K
OW and K
OC) of polychlorinated ...biphenyl (PCBP) congeners identified a number of error sources. A variety of new QSARs were developed based on weighted homogeneity of slopes models. The best type of models used the degree of chlorination in the orthoposition of the PCB molecule as predictor variable together with either the calculated molecular total surface area (TSA) or the gas chromatographic relative retention times (RRT). Prediction of logK
OW and logK
OC for all 209 PCB congeners were based on 53 and 48 experimental data points, respectively. The predicted values were compared to test data sets of 12 and 27 experimental data points, respectively. The QSAR models gave predictions in good agreement with experimental test data.
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