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  • 1.
    Adolfsson-Erici,
    et al.
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Alsberg,
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Magnér,
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Gunnarsson, L.
    Larsson, D.G.J.
    Pharmacuticals in fish bile2007In: SNMM: March 12-14 2007, 2007Conference paper (Other (popular science, discussion, etc.))
  • 2.
    Adolfsson-Erici,
    et al.
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Alsberg,
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Magnér,
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Gunnarsson, L.
    Larsson, D.G.J.
    Tracing pharmaceutical residues from humans to fish2007In: SETAC News: May 20-24, 2007Conference paper (Other (popular science, discussion, etc.))
  • 3.
    Alsberg,
    et al.
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Kärsrud,
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Broms, S.
    Gleisner, M.
    Provningsjämförelse 2007 - Bestämning av petroleumkolväten i standardlösningar, vatten och jord med GC/MS2007Report (Other (popular science, discussion, etc.))
  • 4.
    Alsberg, T
    et al.
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Kärsrud, A
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Gleisner, M.
    Provningsjämförelse 2008 - Bestämning av petroleumkolväten i standardlösningar, vatten och jord med GC/MS2008Report (Other academic)
  • 5.
    Alsberg, T.
    et al.
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Minten, J.
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Haglund, J.
    Stockholm University, Faculty of Science, Department of Environmental Chemistry.
    Törnqvist, M.
    Stockholm University, Faculty of Science, Department of Environmental Chemistry.
    Determination of hydroxyalkyl derivatives of cobalamin (vitamin B12) using reversed phase high performance liquid chromatography with electrospray tandem mass spectrometry and ultraviolet diode array detection2001In: Rapid Communications in Mass Spectrometry, ISSN 0951-4198, E-ISSN 1097-0231, Vol. 15, no 24, p. 2438-45Article in journal (Refereed)
    Abstract [en]

    Electrospray ionization tandem mass spectrometry (ESI-MS/MS) and ultraviolet diode array detection (UV-DAD), coupled on-line to reversed phase high performance liquid chromatography (HPLC), was used for the characterization of hydroxyalkyl derivatives of cob(I)alamin. The reduced form of vitamin B12, cob(I)alamin, denoted a supernucleophile due to its high nucleophilic strength, has shown promise as an analytical tool in studies of electrophilically reactive compounds in vitro and in vivo. A method for analysis of DNA-phosphate adducts was developed earlier utilizing the supernucleophilicity of cob(I)alamin to transfer alkyl groups from the phosphotriester configuration in DNA, with the formation of a Co-substituted alkyl-cobalamin (alkyl-Cbl) complex. For the purpose of identification and quantification of alkyl-Cbls at high sensitivity, an MS/MS method has been developed with application to a number of 2-hydroxyalkyl-cobalamins (OHalkyl-Cbls). The precursor oxiranes were reacted with cob(I)alamin, followed by clean-up and mass spectrometric analysis of the resulting OHalkyl-Cbls. It was found that ionization was highly dependent on solvent composition. By using acetonitrile/water/trifluoroacetic acid (TFA) (eluent I), the base peak was the doubly protonated molecule [M + 2H](2+), whereas acetonitrile/water/1-methylpiperidine (eluent II) yielded the singly protonated molecule [M + H](+) as the base peak. Excellent separation was obtained with eluent II, with good separation between stereoisomers, thus enabling the characterization of these by means of UV spectra. Limits of quantitation for 2-hydroxypropyl-cobalamin (OHPr-Cbl) were 0.2 and 2 pg/microL (or 0.1 and 1 fmol/microL) using selected ion recording (SIR) with eluent I and II, respectively. The obtained detection level should be sufficient for analysis of alkyl-Cbls from a wide range of toxicological applications.

  • 6. Bignert, Anders
    et al.
    Olsson, Mats
    Persson, Wawa
    Jensen, Sören
    Zakrisson, Susanne
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Litzén, Kerstin
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Eriksson, Ulla
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Häggberg, Lisbeth
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Alsberg, Tomas
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Temporal trends of organochlorines in Northern Europe, 1967–1995. Relation to global fractionation, leakage from sediments and international measures1998In: Environmental Pollution, ISSN 0269-7491, E-ISSN 1873-6424, Vol. 99, no 2, p. 177-198Article in journal (Refereed)
    Abstract [en]

    The time trend monitoring of organochlorine pollution was carried out in Sweden since the late 1960s. This report presents data on concentrations of DDT, PCB, HCHs and HCB in biota samples collected and analysed annually. All the matrices and compounds studied show a significant decrease over time. The data cover severely polluted Swedish marine and fresh water in southern Sweden as well as locally unpolluted waters in remote northern Arctic regions of Sweden. A total of 13 time series representing different locations and species are presented for the different pollutants. The period studied covers the time when pollution was serious as well as the time of recovery. All monitoring activities were carried out at the same laboratories over the entire study period, which means that comparability over time is good in the sets of data presented. The various time trends show a convincing agreement with trends and annual change over time, although the concentrations differ between the species and locations investigated, the highest concentrations being in the south. Since the annual changes are normally similar regardless of locations and species, spatial variations in concentrations remain over time, although concentrations are lower today. The onset of changes in concentrations over time can be related to international measures or other circumstances that lowered releases into the environment. Similarities in the annual changes, as well as the time when changes began, are discussed with respect to suggested hypotheses on the fate of the investigated organochlorines. It was not possible to verify that the oxygenation of anoxic sediments mobilised old pollution in Baltic sediments. Neither was it possible to conclude that eutrophication has caused a measurable effect on the rate and timing of the decreases. Finally, long-range transport to Arctic regions seems to be due more to a one step transport than to the ‘Grass-hopper’ effect. The comprehensive database used, clearly shows how important it is to have datasets big enough to describe between-year variation before attempting to evaluate the time trend. In addition, if between-year variation is not known, it is then also difficult to evaluate spatial variation on the basis of single year observations.

  • 7. Bogdal, Christian
    et al.
    Alsberg, Tomas
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Diefenbacher, Pascal S.
    MacLeod, Matthew
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Berger, Urs
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Fast Quantification of Chlorinated Paraffins in Environmental Samples by Direct Injection High-Resolution Mass Spectrometry with Pattern Deconvolution2015In: Analytical Chemistry, ISSN 0003-2700, E-ISSN 1520-6882, Vol. 87, no 5, p. 2852-2860Article in journal (Refereed)
    Abstract [en]

    Chlorinated paraffins (CPs) are high production volume chemicals, but data about their environmental fate are scarce. CP mixtures composed of thousands of isomers represent a major challenge for quantification at low levels in environmental samples. Here, we present a novel analytical method for analysis of short-chain, medium-chain, and long-chain CPs in a single injection, that also yields information about congener group pattern. Our detection method is based on direct injection into an atmospheric pressure chemical ionization source operated in negative ion mode under chlorine-enhanced conditions, followed by quadrupole time-of-flight high-resolution mass spectrometry (APCI-qTOF-HRMS) operated in full-scan mode. A mathematical algorithm is applied to deconvolute the CP patterns in the analyzed samples into a linear combination of patterns of technical CP mixtures and to quantify CPs using technical mixtures as external calibration standards. For CP mixtures with known composition, the new method provided concentrations that were within a factor of 1.2 of the target value. Accuracies for CPs spiked to sediment and fish extracts were between 91% and 123%. Concentrations determined in unspiked field samples were within a factor of 5 for short-chain CPs and a factor of 16 for medium-chain CPs of results obtained with an independent method based on gas chromatography/electron capture negative ionization high-resolution mass spectrometry (GC/ECNI-HRMS). The presented APCI-qTOF-HRMS pattern deconvolution method is an interesting alternative for CP analysis in environmental samples. It is particularly sensitive for medium- and long-chain CPs and has the advantage of being extremely fast (instrumental analysis time, less than 1 min).

  • 8.
    Ekström, S
    et al.
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Alsberg, T
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Hultberg, M.
    Nozière, B
    Nilsson, D
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Artaxo, P.
    “Super-CCN”: A contribution of bio-organisms to cloud formation in Earth’s atmosphere2008In: International Global Atmospheric Chemistry Project (IGAC) 2008: 7-12 September, Annecy, France, 2008Conference paper (Refereed)
  • 9.
    Ekström, Sanna
    et al.
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Nozière, Barbara
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Alsberg, Tomas
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Hultberg, Malin
    Magnér, Jorgen
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Nilsson, E. Douglas
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Artaxo, Paulo
    Of Bacteria and clouds: when microbial substances trigger cloud formation in Earth’s atmosphere2008In: American Geophysical Union Fall Meeting 2008, 2008Conference paper (Refereed)
    Abstract [en]

    This presentation reports the discovery that substances produced by microorganisms might trigger the formation of cloud in the atmosphere, at least under certain conditions.

    The Cloud Condensation Nuclei (CCN) efficiency of substances produced by microorganisms (bacteria, fungi, micro-algae …) that are common at Earth’s surface and in the oceans were studied. Their Köhler curves were determined experimentally by surface tension and osmometry measurements and found to have much lower critical supersaturations than any material studied so far, including inorganic salts.

    The presence of these substances was evidenced in aerosols from four different origins (coastal, marine, temperate forest, and Amazonian forest) by LC/MS/MS analyses and by their unique signature on the surface tension. These substances lowered the surface tension of the aerosols below 40 mN/m, allowing them to be activated into cloud droplets before inorganic particles.

    Microorganisms would thus be able to control cloud formation in Earth’s atmosphere under certain conditions. This would explain many previous observations such as correlations between algae bloom and cloud cover. Most importantly, this work identifies a potentially important component of Earth’s hydrological cycle and a new direct link between biosphere and climate.

  • 10.
    Ekström, Sanna
    et al.
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Nozière, Barbara
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Hultberg, M.
    Alsberg, Tomas
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Magnér, J.
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Nilsson, E. D.
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Artaxo, P.
    A possible role of ground-based microorganisms on cloud formation in the atmosphere2010In: Biogeosciences, ISSN 1726-4170, E-ISSN 1726-4189, Vol. 7, no 1, p. 387-394Article in journal (Refereed)
    Abstract [en]

    The formation of clouds is an important process for the atmosphere, the hydrological cycle, and climate, but some aspects of it are not completely understood. In this work, we show that microorganisms might affect cloud formation without leaving the Earth’s surface by releasing biological surfactants (or biosurfactants) in the environment, that make their way into atmospheric aerosols and could significantly enhance their activation into cloud droplets. In the first part of this work, the cloud-nucleating efficiency of standard biosurfactants was characterized and found to be better than that of any aerosol material studied so far, including inorganic salts. These results identify molecular structures that give organic compounds exceptional cloud-nucleating properties. In the second part, atmospheric aerosols were sampled at different locations: a temperate coastal site, a marine site, a temperate forest, and a tropical forest. Their surface tension was measured and found to be below 30 mN/m, the lowest reported for aerosols, to our knowledge. This very low surface tension was attributed to the presence of biosurfactants, the only natural substances able to reach to such low values. The presence of strong microbial surfactants in aerosols would be consistent with the organic fractions of exceptional cloud-nucleating efficiency recently found in aerosols, and with the correlations between algae bloom and cloud cover reported in the Southern Ocean. The results of this work also suggest that biosurfactants might be common in aerosols and thus of global relevance. If this is confirmed, a new role for microorganisms on the atmosphere and climate could be identified.

  • 11.
    Fred, Charlotta
    et al.
    Stockholm University, Faculty of Science, Department of Environmental Chemistry.
    Haglund, Johanna
    Alsberg, Thomas
    Rydberg, Per
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK), Environmental Chemistry.
    Minten, Johanna
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK), Environmental Chemistry.
    Törnqvist, Margareta
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK), Environmental Chemistry.
    Characterization of alkyl-cobalamins formed in trapping of epoxide metabolites of 1,3-butadiene2004In: Journal of Separation Science, ISSN 1615-9306, E-ISSN 1615-9314, Vol. 27, no 7-8, p. 607-612Article in journal (Refereed)
    Abstract [en]

    Analytical methods facilitating studies of electrophilically reactive and genotoxic compounds in vitro and in vivo are needed. The strong nucleophile, cob(I)alamin, formed by reduction of Vitamin B12 [cob(III)alamin], may be used for trapping and analysis of 1,2-epoxides and other electrophiles. In the present study, cob(I)alamin is evaluated as an analytical tool for 1,2-epoxide metabolites (oxiranes) of 1,3-butadiene. Products of reaction of cob(I)alamin with 1,2-epoxy-3-butene (EB), 1,2:3,4-diepoxybutane (DEB), and 1,2-epoxy-3,4-butanediol (EBdiol) have been analyzed by reversed phase high performance liquid chromatography (HPLC) coupled on-line to electrospray ionization mass spectrometry (ESI-MS) and ultraviolet diode array detection (UV-DAD). It was shown that a specific alkyl-Cbl complex is formed for each metabolite and that it was possible to discriminate between the products by HPLC-UV and by LC-MS. Quantification of DEB with the method by use of another 1,2-epoxide as an internal standard was successfully performed. The possibility of using cob(I)alamin for trapping and analysis of the three oxirane metabolites of 1,3-butadiene will facilitate quantitative comparisons of species in vitro with regard to metabolism of 1,3-butadiene.

  • 12.
    Hedenbrant, Ulla
    et al.
    Stockholm University, Faculty of Science, Department of Environmental Chemistry.
    Haglund, Johanna
    Alsberg, Tomas
    Eriksson, Johan
    Stockholm University, Faculty of Science, Department of Environmental Chemistry.
    Törnqvist, Margareta
    Stockholm University, Faculty of Science, Department of Environmental Chemistry.
    Development of a method for determination of serum albumin adducts of benzo(a)pyrene by LC/ESI-MS2008Conference paper (Other academic)
  • 13. Hultberg, M.
    et al.
    Alsberg, Tomas
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Khalil, S.
    Alsanius, B.
    Suppression of disease in tomato infected by Pythium ultimum with a biosurfactant produced by Pseudomonas koreensis2010In: BioControl (Dordrecht), ISSN 1386-6141, E-ISSN 1573-8248, Vol. 55, no 3, p. 435-444Article in journal (Refereed)
    Abstract [en]

    The use of biosurfactants is a promising alternative in biological control of zoospore-producing oomycetes, which are a major plant pathogen world-wide in a wide variety of crops. Oomycetes are of particular concern in closed hydroponic cultivation systems. The present study investigated the efficacy of a biosurfactant produced by Pseudomonas koreensis and added as a crude extract against the oomycete Pythium ultimum in hydroponic tomato cultivation. A significant reduction in disease was observed. Biosurfactant addition did not affect the indigenous root microflora when evaluated as sole carbon source utilisation. Chemical analysis, using electrospray hybrid mass spectrometry (ESI-MSMS), of the biosurfactant indicated it to be lokisin, a cyclic lipopeptide. These results confirm that biosurfactants are important in developing sustainable biological control strategies for oomycetes.

  • 14.
    Konn, Cécile
    et al.
    Stockholm University, Faculty of Science, Department of Geology and Geochemistry.
    Charlou, Jean-Luc
    Laboratoire de géochimie et métallogénie, Ifremer, Brest, France.
    Magnér, Jörgen
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Holm, Nils
    Stockholm University, Faculty of Science, Department of Geology and Geochemistry.
    Alsberg, Tomas
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Detection of trace concentrations of amino acid in aqueous solutions by Ion-pairing reversed-phase UPLC-ESI-QToF-MS: application to hydrothermal fluidsManuscript (preprint) (Other academic)
    Abstract [en]

    Amino acids are the fundamental building blocks of proteins that are required for the initiation of living organism, therefore they are key compounds in the origin of life quest. The abiotic production of amino acids within ultramafic-hosted hydrothermal systems was suggested a few decades ago and is strongly supported by thermodynamic data and experimental work. However, field data were clearly lacking and thus investigation of amino acids in fluids from ultramafic-hosted hydrothermal systems was of major importance. Even though amino acids analysis have been carried out routinely for several decades in various field of application, none of the currently available methods appeared suitable for our purpose because of the complexity of the hydrothermal fluids matrix (salts, minerals, gases) and the extremely low concentrations of amino acids that were expected. We took up the challenge and here we describe a method to detect underivatized amino acids down to the sub-ppb level in aqueous matrix by ion-pairing reverse-phase Ultra-high Performance Liquid Chromatography - Electrospray Ionisation - Quadrupole Time of Flight - Mass Spectrometry (UPLC-ESI-QTOF-MS). Characterisation and separation of 10 chosen proteinogenic amino acids was achieved and excellent linearity in the response was obtained for all amino acids with correlation coefficient > 0.9921. This analytical method was successfully applied to natural hydrothermal fluid samples from ultramafic-hosted vents of the Mid-Atlantic Ridge region. Tryptophan and Phenylalanine were clearly evidenced in the fluids and concentrations of Leucine reached 15-55 ppt. We suggest that other amino acids are present in hydrothermal fluids but occur for the major part as metal and/or clay complexes and could not be detected using current approach. Finally, concentrations of amino acids measured in the deep seawater reference sample were in good agreement with generally accepted background level in the deep ocean.

  • 15.
    Lavén, M.
    et al.
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Alsberg, Tomas
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Yu, Y.
    Adolfsson-Erici, Margaretha
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Sun, H.
    Serial mixed-mode cation- and anion-exchange solid-phase extraction for separation of basic, neutral and acidic pharmaceuticals in wastewater and analysis by high-performance liquid chromatography-quadrupole time-of-flight mass spectrometry2009In: Journal of Chromatography A, ISSN 0021-9673, E-ISSN 1873-3778, Vol. 1216, no 1, p. 49-62Article in journal (Refereed)
    Abstract [en]

    A novel solid-phase extraction (SPE) method is presented whereby 15 basic, neutral and acidic pharmaceuticals in wastewater were simultaneously extracted and subsequently separated into different fractions. This was achieved using mixed-mode cation- and anion-exchange SPE (Oasis MCX and MAX) in series. Analysis was performed by high-performance liquid chromatography–quadrupole time-of-flight mass spectrometry (HPLC/QTOF-MS). A fast separation was achieved, with all compounds eluting within 6 min, narrow chromatographic peaks, with a peak base width of 6 s on average, and a high mass accuracy of quantified wastewater sample ions, with average mass errors in absolute value of 0.7 mDa or 2.7 ppm. The recovery of the SPE method in the analysis of sewage treatment plant (STP) influent and effluent wastewater was on average 80% and the ion suppression 30%. For less demanding samples Oasis MCX used alone may be an alternative method, although for STP influent waters containing high loads of organic compounds the clean-up achieved using only Oasis MCX was insufficient, leading to unreliable quantitation. Furthermore, serial SPE separation according to molecular charge added an additional degree of analyte confirmation. For quantitation, an approach combining external standard calibration curves, isotopically labelled surrogate standards and single-point standard addition was used. The applicability of the method was demonstrated in the analysis of influent and effluent wastewater from an STP, using small sample volumes (25–50 mL). The effluent wastewater had been subjected to three different treatments; activated sludge, activated sludge followed by ozonation, and a membrane bioreactor (MBR). Ozone treatment proved superior in removal of the analysed pharmaceuticals, while the MBR provided higher removal efficiencies than the activated sludge process.

  • 16.
    Lundström, Elin
    et al.
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Adolfsson-Erici, Margaretha
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Alsberg, Tomas
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Bjorlenius, Berndt
    Eklund, Britta
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Lavén, Martin
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Breitholtz, Magnus
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Characterization of additional sewage treatment technologies: Ecotoxicological effects and levels of selected pharmaceuticals, hormones and endocrine disruptors2010In: Ecotoxicology and Environmental Safety, ISSN 0147-6513, E-ISSN 1090-2414, Vol. 73, no 7, p. 1612-1619Article in journal (Refereed)
    Abstract [en]

    In the present study, two conventional (with and without sand filter) and four additional (moving bed biofilm reactor, ozone, moving bed biofilm reactor combined with ozone and a membrane bio reactor) treatment technologies were operated in small-scale at Hammarby Sjostad sewage treatment plant, Stockholm, Sweden. The effluents were tested with five short-term ( <= 7 days exposure) ecotoxicological tests, and analyzed for a number of target analytes, comprising pharmaceuticals, natural hormones and industrial chemicals. Overall, the tested effluents generated few adverse effects at lower concentrations ( < 50% sewage effluent), and no major differences were observed between any of the treatments. The effluent treated with the moving bed biofilm reactor resulted in the lowest effects in the ecotoxicological tests. The most efficient treatment technology with regard to the pharmaceutical residues was the ozone treatment, which however caused negative effects in some of the ecotoxicological tests.

  • 17.
    Magnér,
    et al.
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Alsberg,
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Broman,
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Passive equilibrium sampling, utilizing a novel polystyrene sampler, to determine the bioavailable part of polar pesticides and pharmaceutical residues in water, sediment and soil.2007In: SETAC Europe, Porto: May 20-24, 2007Conference paper (Other (popular science, discussion, etc.))
  • 18.
    Magnér, Jörgen
    et al.
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Alsberg, Tomas
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Broman, Dag
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Bag-SPE – A convenient extraction method for screening of pharmaceutical-residues in influent and effluent water from sewage treatment plants2009In: Analytical and Bioanalytical Chemistry, ISSN 1618-2642, E-ISSN 1618-2650, Vol. 395, no 5, p. 1481-1489Article in journal (Refereed)
    Abstract [en]

    Bag-SPE is a solid phase extraction (SPE) technique here applied to sample pharmaceutical residues in wastewater. The device consisting of 20 mg polystyrene-divinylbenzene (PS-DVB) enclosed in a woven polyester-fabric was immersed into 20 mL sample. Extraction of the analytes was performed under gentle rotation (25 rpm) until distribution equilibrium was achieved (4 hours). The extraction efficiency for thirteen pharmaceuticals was evaluated for the bag-SPE sampler compared to a conventional SPE cartridge (Oasis HLB). All analyzes were determined on an ultra performance liquid chromatography (UPLC) coupled to a quadrupole time of flight (QToF) mass spectrometer.

    The detection limit of the bag-SPE technique for the analytes in wastewater ranged from 15-100 ng/L with recoveries between 20.7-58.2 % and ion-suppressions between 2.2-53.2 %. Although the extraction efficiencies were lower with the bag-SPE sampler compared to the SPE technique, the two methods showed similar detection limits due to the lower ion-suppression experienced with the bag-SPE. The results demonstrate that bag-SPE is an attractive alternative to the more, in terms of manual handling, demanding SPE-technique.

  • 19.
    Magnér, Jörgen
    et al.
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Alsberg, Tomas
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Broman, Dag
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    The Ability of a Novel Sorptive Polymer to Determine the Freely Dissolved Fraction of Polar Organic Compounds in the Presence of Fulvic Acid or Sediment2009In: Analytical and Bioanalytical Chemistry, ISSN 1618-2642, E-ISSN 1618-2650, Vol. 395, no 5, p. 1525-1532Article in journal (Refereed)
    Abstract [en]

    In the present study, a novel plastic material, poly(ethylene-co-vinyl acetate-co-carbon monoxide) (PEVAC), was evaluated as an absorptive passive equilibrium sampler for determination of the freely dissolved fraction of seven polar organic contaminants (POCs) in the presence of fulvic acid (FA) and sediment. The seven compounds selected were imidacloprid, carbendazim, metoprolol, atrazin, carbamazepine, diazinon and chlorpyrifos, i.e. a mixture of pharmaceuticals and pesticides having logarithmic octanol/water partitioning coefficient (Log KOW) ranging from 0.2 to 4.77.

    The experiments demonstrated that the PEVAC sampler is well suited for determination of the freely dissolved fraction of chemicals in aquatic environments. Generally, the freely dissolved fraction of the POCs decreased with increasing hydrophobicity. However, strong interactions with functional groups of the organic matter seemed to dominate the partitioning for imidacloprid and carbendazim, having logarithmic dissociation partition coefficient (Log D) < 1.47, and for metoprolol which is positively charged at neutral pH.

  • 20.
    Magnér, Jörgen
    et al.
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Filipovic, Marko
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Alsberg, Tomas
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Application of a novel solid-phase-extraction sampler and ultra-performance liquid chromatography quadrupole-time-of-flight mass spectrometry for determination of pharmaceutical residues in surface sea water2010In: Chemosphere, ISSN 0045-6535, E-ISSN 1879-1298, Vol. 80, no 11, p. 1255-1260Article in journal (Refereed)
    Abstract [en]

    In the present study, a multi-residue method based on a bag-solid phase extraction (bag-SPE) technique was evaluated for determination of 10 pharmaceuticals in surface water close to the effluent of a sewage treatment plant (STP) and along a coastal gradient from a STP effluent.

    The 10 compounds selected were caffeine, atenolol, metoprolol, oxazepam, carbamazepine, ketoprofen, naproxen, ibuprofen, diclofenac and gemfibrozil. All analyses were performed using ultra-performance liquid chromatography (UPLC) combined with quadrupole time-of-flight (QTOF) mass spectrometry. The detection limits (LOD) ranged from 1.0 to 13 ng L−1. The method showed linear concentration ranges from 25 to 800 ng L−1 with regression coefficients (R2) better than 0.9801. The recoveries of the selected analytes ranged from 11 to 65% with relative standard deviations (RSD) of <16% and inter-day variations of less than 18%. Isotopically labeled surrogate standards were used to compensate for sampling losses and matrix effects.

    Four of the selected 10 pharmaceuticals (caffeine, metoprolol, oxazepam and carbamazepine) were quantified, at concentrations ranging from 4 to 210 ng L−1.

  • 21.
    Magnér, Jörgen
    et al.
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Filipovic, Marko
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Alsberg, Tomas
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Development of a method for determination of pharmaceutical residues in surface sea water using bag-SPE and UPLC-QToFManuscript (preprint) (Other academic)
    Abstract [en]

    In the present study, a multi-residue method based on a bag –solid phase extraction (bag-SPE) technique was applied to determine the occurrence of ten pharmaceuticals in surface water close to the effluent of a sewage treatment plant (STP) and along a coastal gradient from a STP effluent.

    The ten compounds selected were caffeine, atenolol, metoprolol, oxazepam, carbamazepine, ketoprofen, naproxen, ibuprofen, diclofenac and gemfibrozil, i.e. a mixture of pharmaceuticals of different therapeutic classes having logarithmic octanol/water partitioning coefficients (Log KOW) ranging from -0.13 to 4.39.

    All analyses were performed using ultra performance liquid chromatography (UPLC) combined with quadrupole time-of-flight (QToF) mass spectrometry.

    The detection limit (LOD) of the pharmaceuticals in water ranged from 1.0-13 ng/L. The method showed consistent linear concentration ranges from 25-800 ng/L with regression coefficients (R2) better than 0.9801. The recoveries of the selected analytes ranged from 10.6-64.5 % with relative standard deviations (RSD) of < 16.4 % and inter-day variations of less than 17.7 %.

    Although the detection limits (LOD) of the analytes were low, only four of the selected ten pharmaceuticals (caffeine, metoprolol, oxazepam and carbamazepine) showed concentrations in surface water higher than the detection levels. The concentrations of the four pharmaceuticals in sea water range from 4-210 ng/L.

  • 22.
    McLachlan, Michael S.
    et al.
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Kierkegaard, Amelie
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Radke, Michael
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Sobek, Anna
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Malmvärn, Anna
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Alsberg, Tomas
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Arnot, Jon A.
    Brown, Trevor N.
    Wania, Frank
    Breivik, Knut
    Xu, Shihe
    Using Model-Based Screening to Help Discover Unknown Environmental Contaminants2014In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 48, no 13, p. 7264-7271Article in journal (Refereed)
    Abstract [en]

    Of the tens of thousands of chemicals in use, only a small fraction have been analyzed in environmental samples. To effectively identify environmental contaminants, methods to prioritize chemicals for analytical method development are required. We used a high-throughput model of chemical emissions, fate, and bioaccumulation to identify chemicals likely to have high concentrations in specific environmental media, and we prioritized these for target analysis. This model-based screening was applied to 215 organosilicon chemicals culled from industrial chemical production statistics. The model-based screening prioritized several recognized organosilicon contaminants and generated hypotheses leading to the selection of three chemicals that have not previously been identified as potential environmental contaminants for target analysis. Trace analytical methods were developed, and the chemicals were analyzed in air, sewage sludge, and sediment. All three substances were found to be environmental contaminants. Phenyl-tris(trimethylsiloxy)silane was present in all samples analyzed, with concentrations of similar to 50 pg m(-3) in Stockholm air and similar to 0.5 ng g(-1) dw in sediment from the Stockholm archipelago. Tris(trifluoropropyl)trimethyl-cyclotrisiloxane and tetrakis(trifluoropropyl)tetramethyl-cyclotetrasiloxane were found in sediments from Lake Mjosa at similar to 1 ng g(-1) dw. The discovery of three novel environmental contaminants shows that models can be useful for prioritizing chemicals for exploratory assessment.

  • 23.
    Minten, Johanna
    et al.
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Adolfsson Erici, Margaretha
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Alsberg, Tomas
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Extraction and analysis of pharmaceuticals in pollutedsediment using liquid chromatography mass spectrometry2011In: International Journal of Environmental Analytical Chemistry, ISSN 0306-7319, E-ISSN 1029-0397, Vol. 91, no 6, p. 553-566Article in journal (Refereed)
    Abstract [en]

    A multi-residue method for the extraction and clean-up of sediment samples was developed for the analysis of pharmaceutical residues. Sediment samples were collected in the proximity of sewage water plant in Stockholm, Sweden. Target analytes were the basic -blocker propranolol, the neutral neuroleptic carbamazepine and the acidic anticoagulant warfarin, the painkiller diclofenac and the lipid regulator gemfibrozil. The extraction solvent was optimised with regard to pH and organic modifer. Extraction and clean up were performed with liquid-liquid extraction and ultra-sonication followed by solid-phase extraction. One extraction solvent, containing acetone/McIlvaine buffer pH4, provided satisfactory extraction for all substances. LC/MSMS in the MRM mode was used for determination. The recoveries of the extraction and clean-up steps were 60–75% (2–8%) and LOQs were in the range 0.4–8 ng/g sediment (dry weight). The pharmaceuticals found in the sediment samples were propranolol and carbamazepine, representing substances with basic and neutral properties. Additionally, the samples were analysed with LC/QTOF for verification with the use of accurate mass measurement in the full-scan mode. Pharmaceuticals not represented in the original method were looked for. Non-target pharmaceuticals found using the LC/QTOF system were the basic -blocker metoprolol and the acidic painkiller naproxen.

  • 24.
    Minten, Johanna
    et al.
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Adolfsson Erici, Margaretha
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Björlenius, Berndt
    Stockholm Water Co..
    Alsberg, Tomas
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    A method for the analysis of sucralose with electrosprayLC/MS in recipient waters and in sewage effluent subjected totertiary treatment technologiesManuscript (preprint) (Other academic)
  • 25.
    Minten, Johanna
    et al.
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Adolfsson-Erici, Margaretha
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Bjorlenius, Berndt
    Alsberg, Tomas
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    A method for the analysis of sucralose with electrospray LC/MS in recipient waters and in sewage effluent subjected to tertiary treatment technologies2011In: International Journal of Environmental Analytical Chemistry, ISSN 0306-7319, E-ISSN 1029-0397, Vol. 91, no 4, p. 357-366Article in journal (Refereed)
    Abstract [en]

    A method for the analysis of the artificial sweetener sucralose in sewage water and recipient water was developed. Extraction and clean up was performed with solid-phase extraction utilising Oasis HLB columns. Detection was made by liquid chromatography electrospray mass spectrometry (LC/MS). The triple-quadrupole mass spectrometer was operated in multiple reaction monitoring (MRM) mode. However, 'pseudo MRM' was used, a technique where the two quadrupoles monitor the same m/z. The sodium adduct of sucralose was used for quantification, since lower detection limits were obtained as compared to the sucralose quasi-molecular ion in negative ion mode. The two ions with highest intensity in the chlorine isotope pattern were monitored. The reduction of matrix effects with this approach is discussed. The method limit of quantification (MLOQ) for sewage water was 0.2 mu g L(-1), whereas for recipient water MLOQ was 0.02 mu g L(-1). The method was used to analyse effluent samples from an experimental sewage treatment plant (STP) to assess the efficiency of tertiary treatment techniques for removal of sucralose. Filtration through activated carbon was shown to be efficient, while ozonation, advanced oxidation techniques and membrane bioreactors were less efficient. Analyses of receiving waters showed low dilution of sucralose emitted from the STPs.

  • 26.
    Noziere, Barbara
    et al.
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Ekström, Sanna
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Alsberg, Tomas
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Holmström, Sara
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology (INK).
    Radical-initiated formation of organosulfates and surfactants in atmospheric aerosols2010In: Geophysical Research Letters, ISSN 0094-8276, E-ISSN 1944-8007, Vol. 37, no L05806Article in journal (Refereed)
    Abstract [en]

    Many atmospheric aerosols contain both organic compounds and inorganic material, such as sulfate salts. In this work, we show that these sulfates could trigger some chemical transformations of the organic compounds by producing sulfate radicals, SO4, when exposed to UV light (280–320 nm). In particular, we show by mass spectrometry (LC/ESI-MSMS) that isoprene, methyl vinyl ketone, methacrolein, and α-pinene in irradiated sulfate solutions (ammonium and sodium sulfate) produce the same organosulfates as previously identified in aerosols, and even some that had remained unidentified until now. With a typical time constant of 9 h instead of 4600 days for esterifications, these radical reactions would be a plausible origin for the atmospheric organosulfates. These reactions also produced efficient surfactants, possibly resembling the long-chain organosulfates found in the experiments. Thus, photochemistry in mixed sulfate/organic aerosols could increase cloud condensation nuclei (CCN) numbers, which would be supported by previous atmospheric observations

  • 27.
    Smirnova, Anna
    et al.
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Wincent, Emma
    Vikström Bergander, Linda
    Alsberg, Tomas
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Bergman, Jan
    Rannug, Agneta
    Rannug, Ulf
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Evidence for New Light-Independent Pathways for Generation of the Endogenous Aryl Hydrocarbon Receptor Agonist FICZ2016In: Chemical Research in Toxicology, ISSN 0893-228X, E-ISSN 1520-5010, Vol. 29, no 1, p. 75-86Article in journal (Refereed)
    Abstract [en]

    Activation of the aryl hydrocarbon receptor (AhR), a conserved transcription factor best known as a target for highly toxic halogenated substances such as dioxin, under normal xenobiotic-free conditions is of considerable scientific interest. We have demonstrated previously that a photoproduct of tryptophan, 6-formylindolo[3,2-b]carbazole (FICZ), fulfills the criteria for an endogenous ligand for this receptor and proposed that this compound is the enigmatic mediator of the physiological functions of AhR. Here, we describe novel light-independent pathways by which FICZ can be formed. The oxidant H2O2 was shown to convert tryptophan to FICZ on its own in the absence of light. The enzymatic deamination of tryptamine yielded indole-3-acetaldehyde (I3A), which then rearranged to FICZ and its oxidation product, indolo[3,2-b]carbazole-6-carboxylic acid (CICZ). Indole-3-pyruvate (I3P) also produced I3A, FICZ, and CICZ. Malassezia yeast species, which constitute a part of the normal skin microbiota, produce a number of AhR activators from tryptophan. We identified both FICZ and CICZ among those products. Formation of FICZ from tryptophan or I3P produces a complex mixture of indole derivatives, some of which are CYP1A1 inhibitors. These can hinder the cellular clearance of FICZ and thereby increase its power as an AhR agonist. We present a general molecular mechanism involving dehydrogenations and oxidative coupling for the formation of FICZ in which I3A is the important precursor. In conclusion, our results suggest that FICZ is likely to be formed systemically.

  • 28.
    Ullah, Shahid
    et al.
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Alsberg, Tomas
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Berger, Urs
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Simultaneous determination of perfluoroalkyl phosphonates, carboxylates, and sulfonates in drinking water2011In: Journal of Chromatography A, ISSN 0021-9673, E-ISSN 1873-3778, Vol. 1218, no 37, p. 6388-6395Article in journal (Refereed)
    Abstract [en]

    A trace analytical method based on high performance liquid chromatography coupled to quadrupole time-of-flight high resolution mass spectrometry was developed for simultaneous determination of perfluoroalkyl phosphonates (PFPAs, carbon chain lengths C6,8,10), perfluoroalkyl carboxylates (PFCAs. C5-12), and perfluoroalkyl sulfonates (PFSAs. C4,6,8,10) in drinking water (tap water). Analytes were enriched on a mixed mode co-polymeric sorbent (C8 + quaternary amine) using solid phase extraction. Chromatographic separation was achieved on a Zorbax Extend C18 reversed phase column using a mobile phase gradient consisting of water, methanol, and acetonitrile containing 2 mM ammonium acetate and 5 mM 1-methyl piperidine. The mass spectrometer was operated in electrospray negative ion mode. Use of 1-methyl piperidine in the mobile phase resulted in a significant increase in instrument sensitivity for PFPAs through improved chromatographic resolution, background suppression, and increased ionization efficiency. Method detection limits for extraction of 500 mL tap water were in the ranges of 0.095-0.17 ng/L, 0.027-0.17 ng/L, and 0.014-0.052 ng/L for PFPAs. PFCAs, and PFSAs, respectively. Whole method recoveries at a spiking level of 0.5 ng/L to 500 mL HPLC grade water were 40-56%, 56-97%, and 55-77% for PFPAs, PFCAs. and PFSAs, respectively. A matrix effect (signal enhancement) was observed in the detection of PFPAs in tap water extracts, leading to calculated recoveries of 249-297% at a 0.5 ng/L spiking level. This effect resulted in an additional improvement of method sensitivity for PFPAs. To compensate for the matrix effect. PFPAs in tap water were quantified using matrix-matched and extracted calibration standards. The method was successfully applied to the analysis of drinking water collected from six European countries. PFPAs were not detected except for perfluorooctyl phosphonate (PFOPA) at close to the detection limit of 0.095 ng/L in two water samples from Amsterdam, the Netherlands. Highest levels were found for perfluorobutane sulfonate (PFBS, 18.8 ng/L) and perfluorooctanoate (PFOA, 8.6 ng/L) in samples from Amsterdam as well as for perfluorooctane sulfonate (PFOS, 8.8 ng/L) in tap water from Stockholm, Sweden.

  • 29.
    Ullah, Shahid
    et al.
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Alsberg, Tomas
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Vestergren, Robin
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Berger, Urs
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Determination of perfluoroalkyl carboxylic, sulfonic, and phosphonic acids in food2012In: Analytical and Bioanalytical Chemistry, ISSN 1618-2642, E-ISSN 1618-2650, Vol. 404, no 8, p. 2193-2201Article in journal (Refereed)
    Abstract [en]

    A sensitive and accurate method was developed and validated for simultaneous analysis of perfluoroalkyl carboxylic acids, sulfonic acids, and phosphonic acids (PFPAs) at low picograms per gram concentrations in a variety of food matrices. The method employed extraction with acetonitrile/water and cleanup on a mixed-mode co-polymeric sorbent (C8 + quaternary amine) using solid-phase extraction. High-performance liquid chromatographic separation was achieved on a C18 column using a mobile phase gradient containing 5 mM 1-methyl piperidine for optimal chromatographic resolution of PFPAs. A quadrupole time-of-flight high-resolution mass spectrometer operating in negative ion mode was used as detector. Method detection limits were in the range of 0.002 to 0.02 ng g(-1) for all analytes. Sample preparation (extraction and cleanup) recoveries at a spiking level of 0.1 ng g(-1) to a baby food composite were in the range of 59 to 98 %. A strong matrix effect was observed in the analysis of PFPAs in food extracts, which was tentatively assigned to sorption of PFPAs to the injection vial in the solvent-based calibration standard. The method was successfully applied to a range of different food matrices including duplicate diet samples, vegetables, meat, and fish samples.

  • 30.
    Westberg, Emelie
    et al.
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Hedebrant, Ulla
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Haglund, Johanna
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Alsberg, Tomas
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Eriksson, Johan
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Seidel, Albrecht
    Törnqvist, Margareta
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Conditions for sample preparation and quantitative HPLC/MS-MS analysis of bulky adducts to serum albumin with diolepoxides of polycyclic aromatic hydrocarbons as models2014In: Analytical and Bioanalytical Chemistry, ISSN 1618-2642, E-ISSN 1618-2650, Vol. 406, no 5, p. 1519-1530Article in journal (Refereed)
    Abstract [en]

    Stable adducts to serum albumin (SA) from electrophilic and genotoxic compounds/metabolites can be used as biomarkers for quantification of the corresponding in vivo dose. In the present study, conditions for specific analysis of stable adducts to SA formed from carcinogenic polycyclic aromatic hydrocarbons (PAH) were evaluated in order to achieve a sensitive and reproducible quantitative method. Bulky adducts from diolepoxides (DE) of PAH, primarily DE of benzo[a]pyrene (BPDE) and also DE of dibenzo[a,l]pyrene (DBPDE) and dibenzo[a,h]anthracene (DBADE), were used as model compounds. The alkylated peptides obtained after enzymatic hydrolysis of human SA modified with the different PAHDE were principally PAHDE-His-Pro, PAHDE-His-Pro-Tyr and PAHDE-Lys. Alkaline hydrolysis under optimised conditions gave the BPDE-His as the single analyte of alkylated His, but also indicated degradation of this adduct. It was not possible to obtain the BPDE-His as one analyte from BPDE-alkylated SA through modifications of the enzymatic hydrolysis. The BPDE-His adduct was shown to be stable during the weak acidic conditions used in the isolation of SA. Enrichment by HPLC or SPE, but not butanol extraction, gave good recovery, using Protein LoBind tubes. A simple internal standard (IS) approach using SA modified with other PAHDE as IS was shown to be applicable. A robust analytical procedure based on digestion with pronase, enrichment by HPLC or SPE, and analysis with HPLC/MS-MS electrospray ionisation was achieved. A good reproducibility (coefficient of variation (CV) 11 %) was obtained, and the achieved limit of detection for the studied PAHDE, using standard instrumentation, was approximately 1 fmol adduct/mg SA analysing extract from 5 mg SA.

  • 31.
    Wincent, Emma
    et al.
    Stockholm University, Faculty of Science, Department of Genetics, Microbiology and Toxicology.
    Bengtsson, Johanna
    Stockholm University, Faculty of Science, Department of Genetics, Microbiology and Toxicology.
    Bardbori, Afshin Mohammadi
    Alsberg, Tomas
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Luecke, Sandra
    Rannug, Ulf
    Stockholm University, Faculty of Science, Department of Genetics, Microbiology and Toxicology.
    Rannug, Agneta
    Inhibition of cytochrome P4501-dependent clearance of the endogenous agonist FICZ as a mechanism for activation of the aryl hydrocarbon receptor2012In: Proceedings of the National Academy of Sciences of the United States of America, ISSN 0027-8424, E-ISSN 1091-6490, Vol. 109, no 12, p. 4479-4484Article in journal (Refereed)
    Abstract [en]

    Altered systemic levels of 6-formylindolo[3,2-b]carbazole (FICZ), an enigmatic endogenous ligand for the aryl hydrocarbon receptor (AHR), may explain adverse physiological responses evoked by small natural and anthropogenic molecules as well as by oxidative stress and light. We demonstrate here that several different chemical compounds can inhibit the metabolism of FICZ, thereby disrupting the autoregulatory feedback control of cytochrome P4501 systems and other proteins whose expression is regulated by AHR. FICZ is both the most tightly bound endogenous agonist for the AHR and an ideal substrate for cytochrome CYP1A1/1A2 and 1B1, thereby also participating in an autoregulatory loop that keeps its own steady-state concentration low. At very low concentrations FICZ influences circadian rhythms, responses to UV light, homeostasis associated with pro-and anti-inflammatory processes, and genomic stability. Here, we demonstrate that, if its metabolic clearance is compromised, femtomolar background levels of this compound in cell-culture medium are sufficient to up-regulate CYP1A1 mRNA and enzyme activity. The oxidants UVB irradiation and hydrogen peroxide and the model AHR antagonist 3'-methoxy-4'-nitroflavone all inhibited induction of CYP1A1 enzyme activity by FICZ or 2,3,7,8-tetrachlorodibenzo-p-dioxin, thereby subsequently elevating intracellular levels of FICZ and activating AHR. Taken together, these findings support an indirect mechanism of AHR activation, indicating that AHR activation by molecules with low affinity actually may reflect inhibition of FICZ metabolism and raising questions about the reported promiscuity of the AHR. Accordingly, we propose that prolonged induction of AHR activity through inhibition of CYP1 disturbs feedback regulation of FICZ levels, with potential detrimental consequences.

  • 32.
    Yuan, Bo
    et al.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Alsberg, Tomas
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Bogdal, Christian
    MacLeod, Matthew
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    de Wit, Cynthia
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Modelling isotopic peak distributions of chlorinated paraffins homologue groups in high resolution mass spectrometry in soft ionization modes2015Conference paper (Other academic)
1 - 32 of 32
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