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Ahmed, Trifa Mohammad
Alternative names
Publications (10 of 10) Show all publications
Ahmed, T. M., Bergvall, C. & Westerholm, R. (2018). Emissions of particulate associated oxygenated and native polycyclic aromatic hydrocarbons from vehicles powered by ethanol/gasoline fuel blends. Fuel, 214, 381-385
Open this publication in new window or tab >>Emissions of particulate associated oxygenated and native polycyclic aromatic hydrocarbons from vehicles powered by ethanol/gasoline fuel blends
2018 (English)In: Fuel, ISSN 0016-2361, E-ISSN 1873-7153, Vol. 214, p. 381-385Article in journal (Refereed) Published
Abstract [en]

Emission factors for oxygenated polycyclic aromatic hydrocarbons (OPAHs) and PAHs have been determined from two different fuel flexible light duty vehicles operated at -7 degrees C in the New European Driving Cycle (NEDC) and at +22 degrees C in the Artemis Driving Cycle (ADC). Three different gasoline/ethanol blends, commercially available in Sweden, were tested i.e., gasoline E5, with 5% v/v ethanol and ethanol fuel E85 with 85% v/v ethanol and winter time quality E70 with 70% v/v ethanol, respectively. The results showed greatly increased emissions of both OPAHs and PAHs at cold engine start conditions (-7 degrees C in the NEDC) compared to warm engine start (+ 22 degrees C in the ADC). For the OPAHs, higher average total emission factors were obtained when running on E85 compared to E5 at both cold 2.72 mu g/km vs 1.11 mu g/km and warm 0.19 mu g/km vs 0.11 mu g/km starting conditions with the highest emissions when using E70 at -7 degrees C 4.12 mu g/km. The same trend was found for the PAHs at cold engine start with higher average total emission factors when using ethanol fuel 71.5 mu g/km and 60.0 mu g/km for E70 and E85, respectively compared to gasoline E5 (20.2 mu g/km). Slightly higher average total PAH emissions were obtained when operating at + 22 degrees C with E5 compared to with E85 1.23 mu g/km vs 0.72 mu g/km.

Keywords
Light duty vehicles, Ethanol/gasoline blends, OPAH, PAH
National Category
Chemical Engineering Chemical Sciences
Identifiers
urn:nbn:se:su:diva-151169 (URN)10.1016/j.fuel.2017.11.059 (DOI)000417103800041 ()
Available from: 2018-02-01 Created: 2018-02-01 Last updated: 2022-02-28Bibliographically approved
Sholts, S. B., Smith, K., Wallin, C., Ahmed, T. M. & Wärmlander, S. K. T. (2017). Ancient water bottle use and polycyclic aromatic hydrocarbon (PAH) exposure among California Indians: a prehistoric health risk assessment. Environmental Health, 16, Article ID 61.
Open this publication in new window or tab >>Ancient water bottle use and polycyclic aromatic hydrocarbon (PAH) exposure among California Indians: a prehistoric health risk assessment
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2017 (English)In: Environmental Health, E-ISSN 1476-069X, Vol. 16, article id 61Article in journal (Refereed) Published
Abstract [en]

Background: Polycyclic aromatic hydrocarbons (PAHs) are the main toxic compounds in natural bitumen, a fossil material used by modern and ancient societies around the world. The adverse health effects of PAHs on modern humans are well established, but their health impacts on past populations are unclear. It has previously been suggested that a prehistoric health decline among the native people living on the California Channel Islands may have been related to PAH exposure. Here, we assess the potential health risks of PAH exposure from the use and manufacture of bitumen-coated water bottles by ancient California Indian societies. Methods: We replicated prehistoric bitumen-coated water bottles with traditional materials and techniques of California Indians, based on ethnographic and archaeological evidence. In order to estimate PAH exposure related to water bottle manufacture and use, we conducted controlled experiments to measure PAH contamination 1) in air during the manufacturing process and 2) in water and olive oil stored in a completed bottle for varying periods of time. Samples were analyzed with gas chromatography/mass spectrometry (GC/MS) for concentrations of the 16 PAHs identified by the US Environmental Protection Agency (EPA) as priority pollutants. Results: Eight PAHs were detected in concentrations of 1-10 mu g/m(3) in air during bottle production and 50-900 ng/L in water after 2 months of storage, ranging from two-ring (naphthalene and methylnaphthalene) to four-ring (fluoranthene) molecules. All 16 PAHs analyzed were detected in olive oil after 2 days (2 to 35 mu g/kg), 2 weeks (3 to 66 mu g/kg), and 2 months (5 to 140 mu g/kg) of storage. Conclusions: For ancient California Indians, water stored in bitumen-coated water bottles was not a significant source of PAH exposure, but production of such bottles could have resulted in harmful airborne PAH exposure.

Keywords
PAH, Naphthalene, Bitumen, Asphaltum, Public health, Environmental exposure, Ancient technology
National Category
Earth and Related Environmental Sciences
Identifiers
urn:nbn:se:su:diva-145196 (URN)10.1186/s12940-017-0261-1 (DOI)000404157800001 ()28641573 (PubMedID)
Available from: 2017-07-31 Created: 2017-07-31 Last updated: 2023-02-24Bibliographically approved
Lim, H., Ahmed, T. M., Bergvall, C. & Westerholm, R. (2017). Automated clean-up, separation and detection of polycyclic aromatic hydrocarbons in particulate matter extracts using a 2D-LC/2D-GC system: a method translation from two FIDs to two MS detectors. Analytical and Bioanalytical Chemistry, 409(24), 5619-5629
Open this publication in new window or tab >>Automated clean-up, separation and detection of polycyclic aromatic hydrocarbons in particulate matter extracts using a 2D-LC/2D-GC system: a method translation from two FIDs to two MS detectors
2017 (English)In: Analytical and Bioanalytical Chemistry, ISSN 1618-2642, E-ISSN 1618-2650, Vol. 409, no 24, p. 5619-5629Article in journal (Refereed) Published
Abstract [en]

An online two-dimensional (2D) liquid chromatography/2D gas chromatography system with two mass-selective detectors has been developed on the basis of a previous system with two flame ionization detectors. The method translation involved the change of carrier gas from hydrogen to helium, column dimension and detectors. The 2D system with two mass-selective detectors was validated with use of polycyclic aromatic hydrocarbon (PAH) standards and two standard reference materials from air and diesel exhaust. Furthermore, the system was applied to a real sample, wood smoke particulates. The PAH values determined correlated well with the previous data and those from the National Institute of Standards and Technology. The system enhanced the benefits of the previous system, which were limited by the low detectability and lack of mass selectivity. This study shows an automated 2D system that is valid for PAH analysis of complex environmental samples directly from crude extracts.

Keywords
Polycyclic aromatic hydrocarbon, Multidimensional gas chromatography, Standard reference material, Wood smoke particulates, Long-term stability
National Category
Analytical Chemistry
Research subject
Analytical Chemistry
Identifiers
urn:nbn:se:su:diva-147893 (URN)10.1007/s00216-017-0509-1 (DOI)000409295300002 ()
Available from: 2017-10-23 Created: 2017-10-23 Last updated: 2022-03-23Bibliographically approved
Nyström, R., Sadiktsis, I., Ahmed, T. M., Westerholm, R., Koegler, J. H., Blomberg, A., . . . Boman, C. (2016). Physical and chemical properties of RME biodiesel exhaust particles without engine modifications. Fuel, 186, 261-269
Open this publication in new window or tab >>Physical and chemical properties of RME biodiesel exhaust particles without engine modifications
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2016 (English)In: Fuel, ISSN 0016-2361, E-ISSN 1873-7153, Vol. 186, p. 102p. 261-269Article in journal (Refereed) Published
Abstract [en]

A major contributor to ambient particulate air pollution is exhaust from diesel engines and other vehicles,which can be linked to different adverse health effects. During the last decades, a global drive towardsfinding sustainable and clean bio-based alternative fuels for the transport sector has taken place and biodieselis one of the most established alternatives today. To better assess the overall effects on a publichealth level when introducing biodiesel and other renewable fuels, a better understanding of the detailedexhaust particle properties, is needed. In this work, the physical and chemical properties of biodieselexhaust particles were studied in comparison to standard diesel exhaust emissions, in an existing enginewithout modifications, focusing on particulate carbonaceous matter and PAH/Oxy-PAH as well as fineparticle size distribution. An older off-road engine, produced between 1996 and 2004, was used withthree different fuels/fuel blends; (1) 100 wt% low-sulfur standard petro diesel (SD), (2) 100 wt% rapeseedmethyl ester biodiesel (B100) and (3) a blended fuel – B30 consisting of 30 wt% RME and 70 wt% SD. Thestudy focused mainly on emissions from transient engine operation, but includes also idling conditions.The gaseous emissions measured for the biodiesel fuel were in general in accordance with previousreported data in the literature, and compared to the standard petro diesel the emissions of CO was lowerwhile NOx emissions increased. The particulate mass concentration during transient operation wasalmost halved compared to when petro diesel was used and this was associated with a decrease in averageparticle size. The shift in particle mass and size was associated with a higher fraction of organic matterin general, considerable less PAH’s but a relative higher fraction of Oxy-PAH’s, when shifting frompetro diesel to biodiesel.

Publisher
p. 102
Keywords
Biodiesel, RME, Diesel engine, Exhaust emissions, Particles characteristics, PAH
National Category
Chemical Engineering
Research subject
Analytical Chemistry
Identifiers
urn:nbn:se:su:diva-128855 (URN)10.1016/j.fuel.2016.08.062 (DOI)000385318600027 ()
Available from: 2016-05-12 Created: 2016-04-05 Last updated: 2022-02-23Bibliographically approved
Mohammad Ahmed, T. (2015). Determination of OPAHs and PAHs in Particulate Matter from Ambient Air and Engine Emissions: Multidimensional Chromatography. (Doctoral dissertation). Stockholm: Department of Environmental Science and Analytical Chemistry, Stockholm University
Open this publication in new window or tab >>Determination of OPAHs and PAHs in Particulate Matter from Ambient Air and Engine Emissions: Multidimensional Chromatography
2015 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Particulate matter (PM) is an air pollutant that seriously impacts human health. Epidemiological studies have shown associations between human exposure to urban air PM and lung cancer, respiratory and cardiovascular diseases. Polycyclic aromatic hydrocarbons (PAHs) and oxygenated polycyclic aromatic hydrocarbons (OPAHs) are two groups of compounds associated with PM in ambient air. These compounds are generated from the incomplete combustion of organic material of both natural and anthropogenic origin. PAHs are thought to play an important role in the adverse health outcomes from exposure to PM in air. OPAHs contain one or more carbonyl groups and could be more toxic to humans compared to their corresponding parent PAH. Measurement of these compounds at trace levels in complex matrices requires analytical methods with high selectivity and precision and low quantification limits.

This thesis describes the development and application of analytical methods for the determination of PAHs and OPAHs in ambient air and engine exhaust PM. Extraction was performed using pressurized liquid extraction, and two different setups for liquid chromatography–gas chromatography (LC-GC) were employed for automated sample clean-up, separation and detection. The developed methods were validated using standard reference materials issued by the National Institute of Standards and Technology. The first methodology developed used off-line solid-phase extraction and on-line LC-GC/mass spectrometry (LC-GC/MS). This method provided low limits of quantification and high selectivity and was successfully applied to the determination of OPAHs and PAHs in PM from the urban atmosphere of Sulaymaniyah city in the Kurdistan region of Iraq. The concentration of benzo[a]pyrene in Sulaymaniyah city was three times higher than the legislated EU target value (1 ng/m3). Furthermore the analytical method was applied on exhaust PM of vehicles fuelled with various gasoline/ethanol blends. The emissions factors for PAHs and OPAHs were highest when using70% ethanol/gasoline blends at -7 °C.

The second method developed provided fully automated clean-up, separation and detection of PAHs in PM extracts using a multidimensional 2D-LC/2D-GC system. Polar, mono/di-aromatic and alkane compounds were successively removed by the two-dimensional LC part of the system. Heart-cutting segments from the first GC column (first dimension) to the second GC column (second dimension) increased the resolution of poorly separated or co-eluted PAHs. The results were in good agreement with the certified values from NIST (±25%).

Place, publisher, year, edition, pages
Stockholm: Department of Environmental Science and Analytical Chemistry, Stockholm University, 2015. p. 58
National Category
Analytical Chemistry
Research subject
Analytical Chemistry
Identifiers
urn:nbn:se:su:diva-122046 (URN)978-91-7649-242-0 (ISBN)
Public defence
2015-11-27, Magnélisalen, Kemiska övningslaboratoriet, Svante Arrhenius väg 16 B, Stockholm, 10:00 (English)
Opponent
Supervisors
Note

At the time of the doctoral defense, the following paper was unpublished and had a status as follows: Paper 3: Manuscript.

Available from: 2015-11-05 Created: 2015-10-21 Last updated: 2022-02-23Bibliographically approved
Ahmed, T. M., Bergvall, C., Åberg, M. & Westerholm, R. (2015). Determination of oxygenated and native polycyclic aromatic hydrocarbons in urban dust and diesel particulate matter standard reference materials using pressurized liquid extraction and LC-GC/MS. Analytical and Bioanalytical Chemistry, 407(2), 427-438
Open this publication in new window or tab >>Determination of oxygenated and native polycyclic aromatic hydrocarbons in urban dust and diesel particulate matter standard reference materials using pressurized liquid extraction and LC-GC/MS
2015 (English)In: Analytical and Bioanalytical Chemistry, ISSN 1618-2642, E-ISSN 1618-2650, Vol. 407, no 2, p. 427-438Article in journal (Refereed) Published
Abstract [en]

The objective of this study was to develop a novel analytical chemistry method, comprised of a coupled high-performance liquid chromatography-gas chromatography/mass spectrometry system (LC-GC/MS) with low detection limits and high selectivity, for the identification and determination of oxygenated polycyclic aromatic hydrocarbons (OPAHs) and polycyclic aromatic hydrocarbons (PAHs) in urban air and diesel particulate matter. The linear range of the four OPAHs, which include 9,10-anthraquinone, 4H-cyclopenta[def]phenanthrene-4-one, benzanthrone, and 7,12-benz[a]anthraquinone, was 0.7 pg-43.3 ng with limits of detection (LODs) and limits of quantification (LOQs) on the order of 0.2-0.8 and 0.7-1.3 pg, respectively. The LODs in this study are generally lower than values reported in the literature, which can be explained by using large-volume injection. The recoveries of the OPAHs spiked onto glass fiber filters using two different pressurized liquid extraction (PLE) methods were in the ranges of 84-107 and 67-110 %, respectively. The analytical protocols were validated using the following National Institute of Standards and Technology standard reference materials: SRM 1649a (Urban Dust), SRM 1650b (Diesel Particulate Matter), and SRM 2975 (Diesel Particulate Matter, Industrial Forklift). The measured mass fractions of the OPAHs in the standard reference materials (SRMs) in this present study are higher than the values from the literature, except for benzanthrone in SRM 1649a (Urban Dust). In addition to the OPAHs, 44 PAHs could be detected and quantified from the same particulate extract used in this protocol. Using data from the literature and applying a two-sided t test at the 5 % level using Bonferroni correction, significant differences were found between the tested PLE methods for individual PAHs. However, the measured mass fractions of the PAHs were comparable, similar to, or higher than those previously reported in the literature.

Keywords
OPAHs, PAHs, PLE, SRM1649a, SRM2975, SRM1650b
National Category
Chemical Sciences
Research subject
Analytical Chemistry
Identifiers
urn:nbn:se:su:diva-114258 (URN)10.1007/s00216-014-8304-8 (DOI)000348207200007 ()25395203 (PubMedID)
Note

AuthorCount:4;

Available from: 2015-03-26 Created: 2015-02-25 Last updated: 2022-03-23Bibliographically approved
Ahmed, T. M., Ahmed, B., Aziz, B. K., Bergvall, C. & Westerholm, R. (2015). Native and oxygenated polycyclic aromatic hydrocarbons in ambient air particulate matter from the city of Sulaimaniyah in Iraq. Atmospheric Environment, 116, 44-50
Open this publication in new window or tab >>Native and oxygenated polycyclic aromatic hydrocarbons in ambient air particulate matter from the city of Sulaimaniyah in Iraq
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2015 (English)In: Atmospheric Environment, ISSN 1352-2310, E-ISSN 1873-2844, Vol. 116, p. 44-50Article in journal (Refereed) Published
Abstract [en]

The concentrations of 43 polycyclic aromatic hydrocarbons (PAHs) and 4 oxygenated PAHs (OPAHs) are reported for the first time in particulate matter (PM10) sampled in the air of the city of Sulaimaniyah in Iraq. The total PAH concentration at the different sampling sites varied between 9.3 and 114 ng/m(3). The corresponding values of the human carcinogen benzotalpyrene were between 0.3 and 6.9 ng/m(3), with most samples exceeding the EU annual target value of 1 ng/m(3). The highly carcinogenic dibenzopyrene isomers dibenzo[a,l]pyrene, dibenzo[a,e]pyrene, dibenzo[a,i]pyrene and dibenzo[a,h]pyrene constituted 0.1-0.4% of the total PAH concentration. However, when scaling for relative cancer potencies using toxic equivalency factors, a benzo[a]pyrene equivalent concentration of dibenzo[a,l]pyrene equal to that of benzo[a]pyrene was obtained, indicating that the contribution of dibenzo[a,l]pyrene to the carcinogenicity of the PAHs could be similar to that of benzo[a]pyrene. A high correlation between the determined concentrations of the dibenzopyrene isomers and benzo[a]pyrene was found, which supported the use of benzo[a]pyrene as an indicator for the carcinogenicity of PAHs in ambient air. The total concentrations of the four OPAHs, 9,10-anthraquinone, 4H-cyclopenta[def]phenanthren-4-one, benzanthrone, and 7,12-benz[a]anthraquinone, varied between 0.6 and 8.1 ng/m(3), with 9,10-anthraquinone being the most abundant OPAH in all of the samples.

Keywords
Ambient air, Particulates, Oxygenated polycyclic aromatic hydrocarbons, Polycyclic aromatic hydrocarbons, Benzo[a]pyrene, Dibenzopyrenes, Anthraquinone
National Category
Earth and Related Environmental Sciences Chemical Sciences
Research subject
Analytical Chemistry
Identifiers
urn:nbn:se:su:diva-120178 (URN)10.1016/j.atmosenv.2015.06.020 (DOI)000358469300005 ()
Available from: 2015-09-07 Created: 2015-09-02 Last updated: 2022-02-23Bibliographically approved
Ahmed, T. M., Lim, H., Bergvall, C. & Westerholm, R. (2013). Automated clean-up, separation and detection of polycyclic aromatic hydrocarbons in particulate matter extracts from urban dust and diesel standard reference materials using a 2D-LC/2D-GC system. Analytical and Bioanalytical Chemistry, 405(25), 8215-8222
Open this publication in new window or tab >>Automated clean-up, separation and detection of polycyclic aromatic hydrocarbons in particulate matter extracts from urban dust and diesel standard reference materials using a 2D-LC/2D-GC system
2013 (English)In: Analytical and Bioanalytical Chemistry, ISSN 1618-2642, E-ISSN 1618-2650, Vol. 405, no 25, p. 8215-8222Article in journal (Refereed) Published
Abstract [en]

A multidimensional, on-line coupled liquid chromatographic/gas chromatographic system was developed for the quantification of polycyclic aromatic hydrocarbons (PAHs). A two-dimensional liquid chromatographic system (2D-liquid chromatography (LC)), with three columns having different selectivities, was connected on-line to a two-dimensional gas chromatographic system (2D-gas chromatography (GC)). Samples were cleaned up by combining normal elution and column back-flush of the LC columns to selectively remove matrix constituents and isolate well-defined, PAH enriched fractions. Using this system, the sequential removal of polar, mono/diaromatic, olefinic and alkane compounds from crude extracts was achieved. The LC/GC coupling was performed using a fused silica transfer line into a programmable temperature vaporizer (PTV) GC injector. Using the PTV in the solvent vent mode, excess solvent was removed and the enriched PAH sample extract was injected into the GC. The 2D-GC setup consisted of two capillary columns with different stationary phase selectivities. Heart-cutting of selected PAH compounds in the first GC column (first dimension) and transfer of these to the second GC column (second dimension) increased the baseline resolutions of closely eluting PAHs. The on-line system was validated using the standard reference materials SRM 1649a (urban dust) and SRM 1975 (diesel particulate extract). The PAH concentrations measured were comparable to the certified values and the fully automated LC/GC system performed the clean-up, separation and detection of PAHs in 16 extracts in less than 24 h. The multidimensional, on-line 2D-LC/2D-GC system eliminated manual handling of the sample extracts and minimised the risk of sample loss and contamination, while increasing accuracy and precision.

Keywords
2D-GC, 2D-LC, Benzo[a]pyrene, Heart cut, PAH, SRM1649a, SRM1975
National Category
Analytical Chemistry
Research subject
Analytical Chemistry
Identifiers
urn:nbn:se:su:diva-95076 (URN)10.1007/s00216-013-7222-5 (DOI)000324587400027 ()
Note

AuthorCount:4;

Available from: 2013-10-22 Created: 2013-10-21 Last updated: 2022-02-24Bibliographically approved
Masala, S., Ahmed, T., Bergvall, C. & Westerholm, R. (2011). Improved efficiency of extraction of polycyclic aromatic hydrocarbons (PAHs) from the National Institute of Standards and Technology (NIST) Standard Reference Material Diesel Particulate Matter (SRM 2975) using accelerated solvent extraction. Analytical and Bioanalytical Chemistry, 401(10), 3305-3315
Open this publication in new window or tab >>Improved efficiency of extraction of polycyclic aromatic hydrocarbons (PAHs) from the National Institute of Standards and Technology (NIST) Standard Reference Material Diesel Particulate Matter (SRM 2975) using accelerated solvent extraction
2011 (English)In: Analytical and Bioanalytical Chemistry, ISSN 1618-2642, E-ISSN 1618-2650, Vol. 401, no 10, p. 3305-3315Article in journal (Refereed) Published
Abstract [en]

The efficiency of extraction of polycyclic aromatic hydrocarbons (PAHs) with molecular masses of 252, 276, 278, 300, and 302 Da from standard reference material diesel particulate matter (SRM 2975) has been investigated using accelerated solvent extraction (ASE) with dichloromethane, toluene, methanol, and mixtures of toluene and methanol. Extraction of SRM 2975 using toluene/methanol (9:1, v/v) at maximum instrumental settings (200 A degrees C, 20.7 MPa, and five extraction cycles) with 30-min extraction times resulted in the following elevations of the measured concentration when compared with the certified and reference concentrations reported by the National Institute of Standards and Technology (NIST): benzo[b]fluoranthene, 46%; benzo[k]fluoranthene, 137%; benzo[e]pyrene, 103%; benzo[a]pyrene, 1,570%; perylene, 37%; indeno[1,2,3-cd]pyrene, 41%; benzo[ghi]perylene, 163%; and coronene, 361%. The concentrations of the following PAHs were comparable to the reference values assigned by NIST: indeno[1,2,3-cd]fluoranthene, dibenz[a,h]anthracene, and picene. The measured concentration of dibenzo[a,e]-pyrene was lower than the information value reported by the NIST. The measured concentrations of other highly carcinogenic PAHs (dibenzo[a,l]pyrene, dibenzo[a,i]pyrene, and dibenzo[a,h]pyrene) in SRM 2975 are also reported. Comparison of measurements using the optimized ASE method and using similar conditions to those applied by the NIST for the assignment of PAH concentrations in SRM 2975 indicated that the higher values obtained in the present study were associated with more complete extraction of PAHs from the diesel particulate material. Re-extraction of the particulate samples demonstrated that the deuterated internal standards were more readily recovered than the native PAHs, which may explain the lower values reported by the NIST. The analytical results obtained in the study demonstrated that the efficient extraction of PAHs from SRM 2975 is a critical requirement for the accurate determination of PAHs with high molecular masses in this standard reference material and that the optimization of extraction conditions is essential to avoid underestimation of the PAH concentrations. The requirement is especially relevant to the human carcinogen benzo[a]pyrene, which is commonly used as an indicator of the carcinogenic risk presented by PAH mixtures.

Keywords
Accelerated solvent extraction, ASE, Diesel particulate matter, SRM 2975, PAH, Benzo[a]pyrene, Dibenzo[a, l]pyrene, Dibenzo[a, e]pyrene, Dibenzo[a, i]pyrene, Dibenzo[a, h]pyrene
National Category
Analytical Chemistry
Research subject
Analytical Chemistry
Identifiers
urn:nbn:se:su:diva-65506 (URN)10.1007/s00216-011-5446-9 (DOI)000297159900026 ()
Available from: 2011-12-12 Created: 2011-12-12 Last updated: 2022-02-24Bibliographically approved
Ahmed, T. M., Bergvall, C. & Westerholm, R.Emissions of particulate associated oxygenated and native polycyclic aromatic hydrocarbons from vehicles powered by ethanol/gasoline fuel blends.
Open this publication in new window or tab >>Emissions of particulate associated oxygenated and native polycyclic aromatic hydrocarbons from vehicles powered by ethanol/gasoline fuel blends
(English)Manuscript (preprint) (Other academic)
National Category
Analytical Chemistry
Research subject
Analytical Chemistry
Identifiers
urn:nbn:se:su:diva-122045 (URN)
Available from: 2015-10-21 Created: 2015-10-21 Last updated: 2022-02-23Bibliographically approved
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