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  • 1.
    Avagyan, Rozanna
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    From source to the environment: Strategies for identification and determination of hydroxylated polycyclic aromatic hydrocarbons in complex particulate matrices2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Adverse health effects have been linked to exposure to particulate matter, and wood combustion is considered as an important source of harmful particulate matter in the urban air and environment. Hydroxylated polycyclic aromatic hydrocarbons are a group of compounds with toxic, endocrine disrupting and carcinogenic properties. Sources of hydroxylated polycyclic aromatic hydrocarbons are different incomplete combustion processes, such as coal and wood combustion. They can also be formed by microbiological and/or photochemical degradation of polycyclic aromatic hydrocarbons in the environment.

    This thesis describes analytical strategies and methods that have been developed and used for screening, tentative identification and determination of hydroxylated polycyclic aromatic hydrocarbons in wood combustion and urban air particles. Conventional targeted analytical methods have been developed for compounds with available reference standards, while suspect and non-target screening strategies have been used for the identification of suspects and unknown compounds lacking reference standards. Each step of the developed analytical methods is described and discussed: the choice of the analytical strategy, sampling of the matrices, extraction, clean-up, instrumental analysis, data processing and validation of the methods.

    The influence of wood type (birch, spruce, pine and aspen) and burning conditions (nominal and high burn rate) on the hydroxylated polycyclic aromatic hydrocarbon emissions has been examined, showing that emissions from nominal burn rate combustion correspond on average to 14 % of the emissions from high burn rate combustion. It has been shown that spruce and pine have the highest emissions for nominal burn rate and high burn rate combustion, respectively.

    The composition of wood combustion particles has been examined and 32 suspect hydroxylated polycyclic aromatic hydrocarbons have been tentatively identified together with 20 other oxygen-containing small molecular weight compounds. Furthermore, the presence of hydroxylated polycyclic aromatic hydrocarbons in airborne particles from an urban background and a car tunnel has been investigated, and nine target and 11 suspect hydroxylated polycyclic aromatic hydrocarbons have been determined and tentatively identified, respectively.

    In summary, this thesis has shown that wood combustion is an important emission source of hydroxylated aromatic hydrocarbons and that the chemical composition of the emitted particles strongly depends on both burning conditions and wood type. Furthermore, the findings suggest that there might be other sources of these compounds in the urban environment than wood burning, such as the traffic. Thus, further investigations are required to fully understand the formation, sources and presence of hydroxylated polycyclic aromatic hydrocarbons in the atmosphere. The suitability of different analytical strategies and methods for identification and determination of hydroxylated polycyclic aromatic hydrocarbons is also discussed.

  • 2.
    Avagyan, Rozanna
    et al.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Luongo, Giovanna
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Thorsén, Gunnar
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Östman, Conny
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Benzothiazole, benzotriazole, and their derivates in clothing textiles - a potential source of environmental pollutants and human exposure2015In: Environmental science and pollution research international, ISSN 0944-1344, E-ISSN 1614-7499, Vol. 22, no 8, p. 5842-5849Article in journal (Refereed)
    Abstract [en]

    Textiles play an important role in our daily life, and textile production is one of the oldest industries. In the manufacturing chain from natural and/or synthetic fibers to the final clothing products, the use of many different chemicals is ubiquitous. A lot of research has focused on chemicals in textile wastewater, but the knowledge of the actual content of harmful chemicals in clothes sold on the retail market is limited. In this paper, we have focused on eight benzothiazole and benzotriazole derivatives, compounds rated as high production volume chemicals. Twenty-six clothing samples of various textile materials and colors manufactured in 14 different countries were analyzed in textile clothing using liquid chromatography tandem mass spectrometry. Among the investigated textile products, 11 clothes were for babies, toddlers, and children. Eight of the 11 compounds included in the investigation were detected in the textiles. Benzothiazole was present in 23 of 26 investigated garments in concentrations ranging from 0.45 to 51 μg/g textile. The garment with the highest concentration of benzothiazole contained a total amount of 8.3 mg of the chemical. The third highest concentration of benzothiazole (22 μg/g) was detected in a baby body made from “organic cotton” equipped with the “Nordic Ecolabel” (“Svanenmärkt”). It was also found that concentrations of benzothiazoles in general were much higher than those for benzotriazoles. This study implicates that clothing textiles can be a possible route for human exposure to harmful chemicals by skin contact, as well as being a potential source of environmental pollutants via laundering and release to household wastewater.

  • 3.
    Avagyan, Rozanna
    et al.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Nyström, Robin
    Boman, Christoffer
    Westerholm, Roger
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Determination of hydroxylated polycyclic aromatic hydrocarbons by HPLC-photoionization tandem mass spectrometry in wood smoke particles and soil samples2015In: Analytical and Bioanalytical Chemistry, ISSN 1618-2642, E-ISSN 1618-2650, Vol. 407, no 16, p. 4523-4534Article in journal (Refereed)
    Abstract [en]

    A simple and fast method for analysis of hydroxylated polycyclic aromatic hydrocarbons using pressurized liquid extraction and high performance liquid chromatography utilizing photoionization tandem mass spectrometry was developed. Simultaneous separation and determination of nine hydroxylated polycyclic aromatic hydrocarbons and two hydroxy biphenyls could be performed in negative mode with a run time of 12 min, including equilibration in 5 min. The calibration curves were in two concentration ranges; 1-50 ng/mL and 0.01-50 mu g/mL, with coefficients of correlation R (2) > 0.997. The limits of detection and method quantification limits were in the range of 9-56 pg and 5-38 ng/g, respectively. A two-level full factorial experimental design was used for screening of conditions with the highest impact on the extraction. The extraction procedure was automated and suitable for a large number of samples. The extraction recoveries ranged from 70 to 102 % and the matrix effects were between 92 and 104 %. The overall method was demonstrated on wood smoke particles and soil samples with good analytical performance, and five OH-PAHs were determined in the concentration range of 0.19-210 mu g/g. As far as we know, hydroxylated polycyclic aromatic hydrocarbons were determined in wood smoke and soil samples using photoionization mass spectrometry for the first time in this present study. Accordingly, this study shows that high performance liquid chromatography photoionization tandem mass spectrometry can be a good option for the determination of hydroxylated polycyclic aromatic hydrocarbons in complex environmental samples.

  • 4.
    Avagyan, Rozanna
    et al.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Nyström, Robin
    Lindgren, Robert
    Boman, Christoffer
    Westerholm, Roger
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Particulate hydroxy-PAH emissions from a residential wood log stove using different fuels and burning conditions2016In: Atmospheric Environment, ISSN 1352-2310, E-ISSN 1873-2844, Vol. 140, p. 1-9Article in journal (Refereed)
    Abstract [en]

    Hydroxylated polycyclic aromatic hydrocarbons are oxidation products of polycyclic aromatic hydrocarbons, but have not been studied as extensively as polycyclic aromatic hydrocarbons. Several studies have however shown that hydroxylated polycyclic aromatic hydrocarbons have toxic and carcinogenic properties. They have been detected in air samples in semi urban areas and combustion is assumed to be the primary source of those compounds. To better understand the formation and occurrence of particulate hydroxylated polycyclic aromatic hydrocarbons from residential wood log stove combustion, 9 hydroxylated polycyclic aromatic hydrocarbons and 2 hydroxy biphenyls were quantified in particles generated from four different types of wood logs (birch, spruce, pine, aspen) and two different combustion conditions (nominal and high burn rate). A previously developed method utilizing liquid chromatography photo ionization tandem mass spectrometry and pressurized liquid extraction was used. Polycyclic aromatic hydrocarbons were analyzed along with hydroxylated polycyclic aromatic hydrocarbons. The hydroxylated polycyclic aromatic hydrocarbon emissions varied significantly across different wood types and burning conditions; the highest emissions for nominal burn rate were from spruce and for high burn rate from pine burning. Emissions from nominal burn rate corresponded on average to 15% of the emissions from high burn rate, with average emissions of 218 mu g/MJ(fuel) and 32.5 mu g/MJ(fuel) for high burn rate and nominal burn rate, respectively. Emissions of the measured hydroxylated polycyclic aromatic hydrocarbons corresponded on average to 28% of polycyclic aromatic hydrocarbons emissions. This study shows that wood combustion is a large emission source of hydroxylated polycyclic aromatic hydrocarbons and that not only combustion conditions, but also wood type influences the emissions of hydroxylated polycyclic aromatic hydrocarbons and polycyclic aromatic hydrocarbons. There are few studies that have determined hydroxylated polycyclic aromatic hydrocarbons in emissions from wood combustion, and it is therefore necessary to further investigate the formation, occurrence and distribution of these compounds as they are present in significant amounts in wood smoke particles.

  • 5.
    Avagyan, Rozanna
    et al.
    Stockholm University, Faculty of Science, Department of Analytical Chemistry.
    Sadiktsis, Ioannis
    Stockholm University, Faculty of Science, Department of Analytical Chemistry.
    Bergvall, Christoffer
    Stockholm University, Faculty of Science, Department of Analytical Chemistry.
    Westerholm, Roger
    Stockholm University, Faculty of Science, Department of Analytical Chemistry.
    Tire tread wear particles in ambient air—a previously unknown source of human exposure to the biocide 2-mercaptobenzothiazole2014In: Environmental science and pollution research international, ISSN 0944-1344, E-ISSN 1614-7499, Vol. 21, no 19, p. 11580-11586Article in journal (Refereed)
    Abstract [en]

    Urban particulate matter (PM), asphalt, and tire samples were investigated for their content of benzothiazole and benzothiazole derivates. The purpose of this study was to examine whether wear particles, i.e., tire tread wear or road surface wear, could contribute to atmospheric concentrations of benzothiazole derivatives. Airborne particulate matter (PM10) sampled at a busy street in Stockholm, Sweden, contained on average 17 pg/m3 benzothiazole and 64 pg/m3 2-mercaptobenzothiazole, and the total suspended particulate-associated benzothiazole and 2-mercaptobenzothiazole concentrations were 199 and 591 pg/m3, respectively. This indicates that tire tread wear may be a major source of these benzothiazoles to urban air PM in Stockholm. Furthermore, 2-mercaptobenzothiazole was determined in urban air particulates for the first time in this study, and its presence in inhalable PM10 implies that the human exposure to this biocide is underestimated. This calls for a revision of the risk assessments of 2-mercaptobenzothiazole exposure to humans which currently is limited to occupational exposure.

  • 6.
    Avagyan, Rozanna
    et al.
    Stockholm University, Faculty of Science, Department of Analytical Chemistry.
    Sadiktsis, Ioannis
    Stockholm University, Faculty of Science, Department of Analytical Chemistry.
    Thorsen, Gunnar
    Stockholm University, Faculty of Science, Department of Analytical Chemistry.
    Östman, Conny
    Stockholm University, Faculty of Science, Department of Analytical Chemistry.
    Westerholm, Roger
    Stockholm University, Faculty of Science, Department of Analytical Chemistry.
    Determination of benzothiazole and benzotriazole derivates in tire and clothing textile samples by high performance liquid chromatography-electrospray ionization tandem mass spectrometry2013In: Journal of Chromatography A, ISSN 0021-9673, E-ISSN 1873-3778, Vol. 1307, p. 119-125Article in journal (Refereed)
    Abstract [en]

    A high performance liquid chromatography–tandem mass spectrometry method utilizing electrospray ionization in positive and negative mode has been developed for the separation and detection of benzothiazole and benzotriazole derivates. Ultra-sonication assisted solvent extraction of these compounds has also been developed and the overall method demonstrated on a selected clothing textile and an automobile tire sample. Matrix effects and extraction recoveries, as well as linearity and limits of detection have been evaluated. The calibration curves spanned over more than two orders of magnitude with coefficients of correlation R2 > 0.99 and the limits of detection and the limits of quantification were in the range 1.7–58 pg injected and 18–140 pg/g, respectively. The extraction recoveries ranged between 69% and 102% and the matrix effects between 75% and 101%. Benzothiazole and benzotriazole derivates were determined in the textile sample and benzothiazole derivatives determined in the tire sample with good analytical performance.

  • 7.
    Avagyan, Rozanna
    et al.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Westerholm, Roger
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Target and suspect screening of OH-PAHs in air particulate using liquid chromatography- orbitrap high resolution mass spectrometryManuscript (preprint) (Other academic)
  • 8.
    Avagyan, Rozanna
    et al.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Westerholm, Roger
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Target and suspect screening of OH-PAHs in air particulates using liquid chromatography-orbitrap high resolution mass spectrometry2017In: Talanta: The International Journal of Pure and Applied Analytical Chemistry, ISSN 0039-9140, E-ISSN 1873-3573, Vol. 165, p. 702-708Article in journal (Refereed)
    Abstract [en]

    Up until now, the methods used for determination of hydroxylated polycyclic aromatic hydrocarbons in air particulate samples have been target methods, only determining compounds with available reference standards. In this present study, a combined target and suspect screening strategy for the analysis of hydroxylated polycyclic aromatic hydrocarbons was developed, utilizing liquid chromatography coupled to orbitrap high resolution mass spectrometry. The target screening included simultaneous determination of nine hydroxylated polycyclic aromatic hydrocarbons, while additional eight hydroxylated polycyclic aromatic hydrocarbon masses were screened for using the suspect screening. The target screening was validated with respect to linearity, limits of detection and quantification and matrix effects. The calibration curves ranged from 0.01 to 10 ng/mL, the method limits of detection and. quantification were in the rage of 0.001-0.018 pg/m(3) and 0.006-0.061 pg/m(3), respectively, while matrix effects ranged from 83% to 104%. For the suspect screening, a list with expected precursor ions created from suspect monoisotopic masses was used. The suspects were then identified by the accurate exact mass, with a mass accuracy threshold < 5 ppm, molecular formula, isotopic pattern, and mass spectra (fragments) and also semi-quantified in order to obtain information on their relative levels in different matrixes. The developed strategy was applied on five air particulate samples collected from an urban background and five samples from a car tunnel in Stockholm (Sweden). In total 20 hydroxylated polycyclic aromatic hydrocarbons were detected, of which nine compounds were determined using the target screening and 11 were tentatively identified and semi-quantified using the suspect screening strategy. The concentrations of the target compounds ranged from 20.7 to 96.9 pg/m(3), for most of the analytes the concentrations in particles from car tunnel were slightly higher than in urban air particles. The levels of most of the tentatively identified compounds were also slightly higher in particles from the car tunnel.

  • 9.
    Avagyan, Rozanna
    et al.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Åberg, Magnus
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Westerholm, Roger
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Suspect screening of OH-PAHs and non-target screening of other organic compounds in wood smoke particles using HR-Orbitrap-MS2016In: Chemosphere, ISSN 0045-6535, E-ISSN 1879-1298, Vol. 163, p. 313-321Article in journal (Refereed)
    Abstract [en]

    Wood combustion has been shown to contribute significantly to emissions of polycyclic aromatic hydrocarbons and hydroxylated polycyclic aromatic hydrocarbons, compounds with toxic and carcinogenic properties. However, only a small number of hydroxylated polycyclic aromatic hydrocarbons have been determined in particles from wood combustion, usually compounds with available reference standards. In this present study, suspect and non-target screening strategies were applied to characterize the wood smoke particles from four different wood types and two combustion conditions with respect to hydroxylated polycyclic aromatic hydrocarbons and other organic compounds. In the suspect screening, 32 peaks corresponding to 12 monohydroxylated masses were tentatively identified by elemental composition assignments and matching of isotopic pattern and fragments. More than one structure was suggested for most of the measured masses. Statistical analysis was performed on the non-target screening data in order to single out significant peaks having intensities that depend on the wood type and/or combustion condition. Significant peaks were found in both negative and positive ionization modes, with unique peaks for each wood type and combustion condition, as well as a combination of both factors. Furthermore, structural elucidation of some peaks was done by comparing the spectra in the samples with spectra found in the spectral databases. Six compounds were tentatively identified in positive ionization mode, and 19 in negative ionization mode. The results in this present study demonstrate that there are significant overall differences in the chemistry of wood smoke particles that depends on both the wood type and the combustion condition used.

  • 10.
    Luongo, Giovanna
    et al.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Avagyan, Rozanna
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Hongyu, Ren
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Östman, Conny
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    The washout effect during laundry on benzothiazole, benzotriazole, quinoline, and their derivatives in clothing textiles2016In: Environmental science and pollution research international, ISSN 0944-1344, E-ISSN 1614-7499, Vol. 23, no 3, p. 2537-2548Article in journal (Refereed)
    Abstract [en]

    In two previous papers, the authors have shown that benzothiazole, benzotriazole, quinoline, and several of their derivatives are widespread in clothing textile articles. A number of these compounds exhibit allergenic and irritating properties and, due to their octanol-water partition coefficient, are prone to be absorbed by the skin. Moreover, they are slightly soluble in water, which could make washing of clothes a route of emission into the environment. In the present study, the washout effect of benzothiazole, benzotriazole, quinoline, and some of their derivatives has been investigated. Twenty-seven textile samples were analyzed before, as well as after five and ten times of washing. The most abundant analyte was found to be benzothiazole, which was detected in 85 % of the samples with an average concentration of 0.53 mu g/g (median 0.44 mu g/g), followed by quinoline, detected in 81 % of the samples with an average concentration of 2.42 mu g/g (median 0.21 mu g/g). The average decrease in concentration for benzothiazoles was 50 % after ten times washing, while it was around 20 % for quinolines. The average emission to household wastewater of benzothiazoles and quinolines during one washing (5 kg of clothes made from polyester materials) was calculated to 0.5 and 0.24 g, respectively. These results strongly indicate that laundering of clothing textiles can be an important source of release of these compounds to household wastewater and in the end to aquatic environments. It also demonstrates a potential source of human exposure to these chemicals since considerable amounts of the compounds remain in the clothes even after ten times of washing.

  • 11. Nyström, Robin
    et al.
    Lindgren, Robert
    Avagyan, Rozanna
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Westerholm, Roger
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Lundstedt, Staffan
    Boman, Christoffer
    Influence of Wood Species and Burning Conditions on Particle Emission Characteristics in a Residential Wood Stove2017In: Energy & Fuels, ISSN 0887-0624, E-ISSN 1520-5029, Vol. 31, no 5, p. 5514-5524Article in journal (Refereed)
    Abstract [en]

    Emissions from small-scale residential biomass combustion are a major source of indoor and outdoor particulate matter (PM) air pollution, and the performance of stoves, boilers, and fireplaces have been shown to be influenced both by fuel properties, technology, and user behavior (firing procedures). Still, rather scarce information is available regarding the relative importance of these variables for the particle characteristics and emissions of different particulate components, e.g., soot, polycyclic aromatic hydrocarbons (PAHs), oxy-PAH, and metals. In particular, the behavior of different wood fuels under varying firing procedures and combustion conditions has not been studied thoroughly. Therefore, the objective of this work was to elucidate the influence of wood species and combustion conditions on particle emission characteristics in a typical Nordic residential wood stove. The emissions from four different wood species were investigated at two controlled combustion conditions, including nominal and high burn rates, with a focus on physical and chemical properties of the fine particulate matter. Considerably elevated carbonaceous particle emissions (soot and organics) were found during high burn rate conditions, which were associated with a shift in particle number size distribution toward a higher fraction of larger particles. In some cases, as here seen for pine, the specific fuel properties can affect the combustion performance and thereby also influence particle and PAH emissions. For the inorganic ash particles, the content in the fuel, and not burning conditions, was found to be the main determining factor, as seen by the increased emissions of alkali salts for aspen. Wood stove emission data on 11 specific oxy-PAHs, together with 45 PAHs, were combined with controlled variations of burning conditions and fuels. The oxy-PAH/PAH ratio during a high burn rate was observed to increase, suggesting an enrichment of particulate oxy-PAH. Accordingly, the main influence on emission performance and particle characteristics was seen between different burn rates, and this study clearly illustrates the major importance of proper operation to avoid unfavorable burning condition, regardless of the wood species used.

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