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  • 1.
    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.

  • 2.
    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.

  • 3.
    Minten, Johanna
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Development of analytical methods for two applications of environmental interest using liquid chromatography.2007Licentiate thesis, monograph (Other academic)
  • 4.
    Minten, Johanna
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Development of Methods for the Analysis of Polar Compounds in Environmental Matrices using LC/UV and LC/MS2009Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    In recent years, the awareness of environmentally hazardous compounds with polar and ionizable properties has intensified. Pharmaceuticals, the pesticide tebuconazole as well as the artificial sweetener sucralose are examples of such new, emerging, contaminants. The toxicological and ecotoxicological effects of these contaminants require investigation. This has led to an increasing need for analytical methods capable of measuring polar compounds in environmental matrices.

     This thesis describes the use of liquid chromatography (LC) hyphenated with ultraviolet (UV) or mass spectrometric (MS) detection for four environmental applications. Paper I describes a method for the detection and qualitative analysis of hydroxyalkyl cobalamins using LC/MS. The method was part of a project for the determination of carcinogenic compounds bound as adducts to the DNA molecule. In paper II, a LC/UV method for the analysis of the pesticide tebuconazole was developed. The method was used to evaluate a novel ecotoxicological test system. Paper III describes an LC/MS method for the determination of the artificial sweetener sucralose in sewage and recipient water. The sucralose molecule and its fragments were found difficult to detect, and a method was developed as an alternative to multiple reaction monitoring (MRM). Both quadrupoles scanned the same ion, a novel technique hypothesized to reduce matrix effects compared to selected ion recording (SIR). Paper IV describes a method for the extraction and analysis of pharmaceuticals in sediment. The study emphasizes the evaluation of suitable solvents for the extraction of basic, neutral and acidic pharmaceuticals. It was concluded that an extraction solvent containing acetone : McIlvaine buffer (pH 4) was appropriate. Electrospray LC/MS in the MRM mode was used. Additional qualitative identification of non target pharmaceuticals was performed by accurate mass measurements utilizing a quadrupole time-of-flight (Q/TOF) instrument.

  • 5.
    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)
  • 6.
    Minten, Johanna
    et al.
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Adolfsson-Erici,
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Ulfsdotter Turesson, E.
    Stiernström,
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Breitholtz,
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Utveckling av en analysmetod för pesticiden tebuconazole med vätskekromatografi och UV-diode-array detektor avsett för att utvärdera ett ekotoxikologiskt testsystem där den bentiska sötvattenorganismen Attheyella crassa exponerats för tebuconazole2007In: SNMM: March 12-14 2007, 2007Conference paper (Other (popular science, discussion, etc.))
  • 7.
    Stiernström,
    et al.
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Ulfsdotter Turesson, E.
    Minten,
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Adolfsson-Erici,
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Bengtsson, Bengt-Erik
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Breitholtz,
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    A novel reproduction and development sediment toxicity test with the freshwater harpacticoid copepod /Attheyella crassa/.2007In: SETAC 17th Annual Meeting in Europe, Porto, Portugal: 20-24 May, 2007Conference paper (Other (popular science, discussion, etc.))
  • 8.
    Ulfsdotter Turesson, Eva
    et al.
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Stiernström, Sara
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Minten, Johanna
    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).
    Bengtsson, Bengt-Erik
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Breitholtz, Magnus
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Development and reproduction of the freshwater harpacticoid copepod Attheyella crassa for assessing sediment-associated toxicity2007In: Aquatic Toxicology, ISSN 0166-445X, E-ISSN 1879-1514, Vol. 83, no 3, p. 180-9Article in journal (Refereed)
    Abstract [en]

    Both freshwater and marine sediments are sinks for many anthropogenic substances. This may pose a risk to benthic and epibenthic organisms and it is crucial that toxicity tests that are available for environmental risk assessment can identify potentially adverse effects of sediment-associated substances on benthic organisms, such as harpacticoid copepods. While marine harpacticoids have been protected via a number of acute and chronic sediment tests, the freshwater harpacticoid copepod community has so far been neglected in such activities. The main aim of the present study was therefore to (a) find a suitable freshwater harpacticoid copepod, (b) establish robust laboratory mass cultures and (c) develop a chronic test for assessment of sediment-associated toxicity using spiked sediments. After several cultivation trials with a number of potential test species, the choice fell on the benthic freshwater harpacticoid copepod Attheyella crassa, a species that possesses many of the characteristic features identified as prerequisites for toxicity test organisms, e.g. it has a sexual reproduction, it is relatively easy to grow and keep in mass cultures in the laboratory, and it has a small body size. Owing to the relatively long generation time of freshwater harpacticoids (in relation to many marine harpacticoids), it was decided that the test should be separated into a development part (21 days) and a reproduction part (14 days) running in parallel. As a reference substance we used the fungicide tebuconazole, which is currently subject to risk assessment and which partitions to soil and sediment. Clear concentration-related responses were observed for all endpoints analyzed. Nauplia body length was the most sensitive endpoint with a measured time weighted LOEC(water) of 20microg/L. The corresponding LOEC(water) for larval mortality and offspring production was 65 and 62microg/L, respectively. In conclusion, A. crassa is an ecologically relevant test species for freshwater ecosystems and particularly for the cold, oligotrophic and often acidic lakes of Northern Europe. Regardless of the relatively long generation time of this species, our results clearly show that sediment-associated toxicity related to development and sexual reproduction can be assessed within 2-3 weeks exposure with the developed bioassay.

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