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  • 1.
    Blum, Kristin M
    et al.
    Department of Chemistry, Umeå University.
    Norström, Sara
    Department of Chemistry, Umeå University.
    Golokov, Oksana
    South Bohemian Research Center of Aquaculture and Biodiversity of Hydrocenoses, Vodnany, Czech Republic.
    Graic, Roman
    South Bohemian Research Center of Aquaculture and Biodiversity of Hydrocenoses, Vodnany, Czech Republic.
    Järhult, Josef D.
    Department of Medical Sciences, Uppsala University; Department of Medical Biochemistry and Microbiology, Uppsala University.
    Koba, Olga
    South Bohemian Research Center of Aquaculture and Biodiversity of Hydrocenoses, Vodnany, Czech Republic.
    Söderström Lindström, Hanna
    Department of Chemistry, Umeå University; Occupational and Environmental Medicine, Umeå University.
    Removal of 30 active pharmaceutical ingredients in surface water under long-term artificial UV irradiation2017In: Chemosphere, ISSN 0045-6535, E-ISSN 1879-1298, Vol. 176, p. 175-182Article in journal (Refereed)
    Abstract [en]

    This study investigated the i) kinetics, and ii) proportion of photolysis of 30 relatively stable active pharmaceutical ingredients (APIs) during artificial UV irradiation for 28 d in ammonium acetate buffer, filtered and unfiltered river water. Buffer was included to control removal kinetics under stable pH conditions and without particulate matter. Dark controls were used to determine removal due to other processes than photolysis and calculate the proportion of photolysis of the total removal. The removal of each API in each matrix was determined using online solid phase extraction/liquid chromatography tandem mass spectrometry (online SPE/LC-MS/MS). Most APIs transformed during the 28 d of UV irradiation and the dark controls showed that photolysis was the major removal process for the majority of the APIs studied. The half-lives ranged from 6 h (amitriptyline) in unfiltered river water to 884 h (37 d, carbamazepine) in buffer. In unfiltered river water, the proportion of APIs with short half-lives (<48 h) was much higher (29%) than in the other matrices (4%), probably due to additional organic carbon, which could have promoted indirect photolysis. Furthermore, two APIs, memantine and fluconazole, were stable in all three matrices, while alprazolam was stable in buffer and unfiltered river water and four additional APIs were stable in buffer. Considering the relatively long-term UV-exposure, this study enabled the investigation of environmentally relevant half-lives in natural waters. Many APIs showed high persistence, which is environmentally concerning and emphasizes the importance of further studies on their environmental fate and effects.

  • 2.
    Bylund, Dan
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Norström, Sara
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Essén, Sofia
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Lundström, Ulla
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Analysis of low molecular mass organic acids in natural waters by ion exclusion chromatography tandem mass spectrometry2007In: Journal of Chromatography A, ISSN 0021-9673, E-ISSN 1873-3778, Vol. 1176, no 1-2, p. 89-93Article in journal (Refereed)
    Abstract [en]

    A sensitive and selective method for the analysis of aliphatic low molecular mass organic acids (LMMOAs) in natural waters is presented. The method is based on separation with ion exclusion chromatography and detection with electrospray ionization tandem mass spectrometry (LC-MS/MS). The extra selectivity gained by applying MS/MS allows for a minimum of sample preparation and the use of a sub-optimal mobile phase regarding chromatographic resolution. Instead the mobile phase, comprising aqueous formic acid With methanol as organic modifier, was mainly optimized for maximum sensitivity and long term MS stability. Detection limits for malonic, fumaric, maleic, succinic, citraconic, glutaric, malic, alpha-ketoglutaric, tartaric, shikimic, trans-aconitic, cis-aconitic, isocitric and citric acid were in the range 1-50 nM, while the detection limits for pyruvic, oxalic and lactic acid were around 250 nM for an injection volume of 100 mu L. Due to their metal-chelating properties, these LMMOAs are all considered to affect the bioavailability of metals and to be involved in soil forming processes. It is thus of interest to be able to monitor their presence in natural waters, and the method developed within this work was successfully applied for the analysis of LMMOAs in soil solution and stream water samples.

  • 3.
    Fransson, Petra
    et al.
    Swedish Univ Agr Sci, Uppsala BioCtr, Dept Forest Mycol & Plant Pathol, Uppsala, Sweden.
    Andersson, Alexandra
    Swedish Univ Agr Sci, Uppsala BioCtr, Dept Forest Mycol & Plant Pathol, Uppsala, Sweden.
    Norström, Sara
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences. Umeå Univ, Dept Chem, SE-90187 Umeå, Sweden.
    Bylund, Dan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Bent, Elizabeth
    Univ Guelph, Sch Environm Sci, Guelph, ON N1G 2W1, Canada.
    Ectomycorrhizal exudates and pre-exposure to elevated CO2 affects soil bacterial growth and community structure2016In: Fungal ecology, ISSN 1754-5048, E-ISSN 1878-0083, Vol. 20, p. 211-224Article in journal (Refereed)
    Abstract [en]

    Ectomycorrhizal fungi produce low molecular weight organic compounds, supporting diverse microbial communities. To link mycorrhizal root exudation directly to bacterial responses, we used Scots pine exudates with (Suillus variegatus and Piloderma fallax) and without mycorrhiza as substrata for forest soil bacteria. Bacterial growth and vitality was monitored, and community composition determined using TRFLP, cloning and sequencing. We investigated if the amount of organic acids in exudates explained bacterial growth, and whether bacterial communities were influenced by pre-exposure to elevated atmospheric CO2. We demonstrated functional differences in bacterial growth rates related to CO2. There was a shift in the bacterial community (e.g. Burkholderia sp. and gamma-proteobacteria) toward organisms better able to rapidly utilize exudates when pine microcosms were pre-exposed to elevated CO2. Soil bacteria from all treatments tended to grow more abundantly and rapidly in exudates from Pilo derma -colonized seedlings, suggesting that the organic acids and/or unidentified compounds present supported greater growth.

  • 4.
    Lundström, Ulla S
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Norström, Sara H
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Vestin, Jenny L K
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Essén, Sofia A
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Bylund, Dan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Dissolved Organic Matter Dynamics of Soil and Stream Water in a Catchment Area, Keynote speaker2006Conference paper (Other scientific)
  • 5.
    Norström, Sara
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Seasonal variations of the water chemistry of a catchment area: Poster2005Other (Other academic)
  • 6.
    Norström, Sara
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Bylund, Dan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Lundström, Ulla
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Vestin, Jenny
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Aronsson, Andreas
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Influence of dissolved organic carbon (DOC) on the water chemistry in two forested catchments2007In: Proceedings. International Humic Substances Society.11 th Nordic-Baltic Symposium, Functioning of NOM in Environment, Joensuu, Finland June 10-13, 2007, 2007Conference paper (Refereed)
  • 7.
    Norström, Sara
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Bylund, Dan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Vestin, Jenny L K
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Lundström, Ulla S
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Initial effects of wood ash application on the stream water chemistry in a boreal catchment in central Sweden2011In: Water, Air and Soil Pollution, ISSN 0049-6979, E-ISSN 1573-2932, Vol. 221, no 1-4, p. 123-136Article in journal (Refereed)
    Abstract [en]

    Due to increased whole-tree harvesting in Swedish forestry, concern has been raised that a depletion of nutrients in forest soil will arise. The Swedish Forest Agency recommends compensation fertilization with wood ash to ensure that unwanted effects are avoided in the nutrient balance of the forest soil and in the quality of surface water. In this investigation, the chemistry of two first-order streams, of which one was subjected to a catchment scale treatment with 3 tonnes of self-hardened wood ash/ha in the fall of 2004, was monitored during 2003-2006. Large seasonal variations in stream water chemistry made changes due to ash application difficult to detect, but evaluating the ash treatment effects through comparison of the stream water of the treated catchment with the reference was possible via statistical tools such as randomized intervention analysis in combination with cumulative sum charts. The wood ash application did not yield any significant effect on the pH in the stream water and hence did not affect the bicarbonate system. However, dissolved organic carbon increased, a previously unreported effect of WAA, bringing about an increase of organic anions in the stream water. The wood ash application also induced significant increases for Ca, Mg, K, Si, Cl and malonate, of which K was most prominent. Although significant, the changes induced by the wood ash application were all small compared to the seasonal variations. As a tool to counteract acidification of surface waters, WAA seems to have limited initial effects

  • 8.
    Norström, Sara H
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Soil and stream water chemistry in a boreal catchment - interactions, influences of dissolved organic matter and effects of wood ash application2010Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Two small bordering catchments in Bispgården, Central Sweden, wereinvestigated in regard to soil solution and stream water chemistry during the frostfree seasons of 2003-2007. Both catchments were drained by first order streams,Fanbergsbäcken and Gråbergsbäcken, and in Fanbergsbäckens catchment anextensive investigation of the soil and soil solution chemistry was conducted bylysimeter and centrifugation sampling. The area of intensive soil solutioninvestigation was situated in a slope towards a stream incorporating a rechargearea, with podzolic soil, and a discharge area close to the stream with an arenosolsoil. Samples were continuously taken in both the recharge- and the discharge areaof the slope, and stream water was sampled in the streams of both catchments. Themain variables of interest of the study were the interactions, the influence ofdissolved organic carbon and the effects of wood ash application to soil solutionand stream water.The natural variations and the interactions between soil solution and streamwater were monitored during 2003-2004. In soil solution, most of the investigatedsubstances tended to increase during the growing season, due to weathering andmicrobial degradation of biota. Ca, Mg, Al and Fe were highly associated todissolved organic carbon (DOC) throughout the catchment. The low molecularfraction of DOC seemed to have a higher impact on the soil processes in therecharge area, while high molecular DOC was more important for transport ofcations in the discharge area and the stream water.The concentration of different substances in the two streams differedsignificantly, even though the catchments were similar in size, shape andforestation. The seasonal patterns of most of the substances measured weresignificantly correlated between the streams, however. Cations and pH correlatedwell with DOC and flow. The flow pattern driven by precipitation seems to be thedriver of the stream water chemistry.Wood ash was applied at a dosage of 3 ton/ha to one of the catchments in theautumn of 2004, to investigate the initial effects on the soil solution- and streamwater chemistry. WAA is recommended by the Swedish Forest Agency tocounteract acidification in soil and runoff that may be caused by an intensivebiomass harvesting. The impact of the WAA was studied during 2005-2006.Compared to the control temporarily higher concentrations of K, Ca and SO4 wereobserved in the soil solution of the ashed area. In the stream water the effects of theWAA were easier to distinguish due to higher sampling frequency. The strongesteffect was seen for K, but increases in the stream water were also noted for DOC,Ca, Mg, Si, Cl and malonate. No increase in pH could be statistically verifiedhowever, and overall the initial effects of the WAA seem mild.

  • 9.
    Norström, Sara H
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of applied science and design.
    Bylund, Dan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of applied science and design.
    Vestin, Jenny L. K.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of applied science and design.
    Lundström, Ulla S
    Mid Sweden University, Faculty of Science, Technology and Media, Department of applied science and design.
    Initial effects of wood ash application to soil and soil solution chemistry in a small, boreal watershed2012In: Geoderma, ISSN 0016-7061, E-ISSN 1872-6259, Vol. 187, p. 85-93Article in journal (Refereed)
    Abstract [en]

    With the conception that whole tree harvesting leads to an impoverishment of forest soils wood ash application is recommended, with the foremost benefits being increased pH in soil and subsequent surface waters, and recycling of nutrients from the wood ash.

    In this investigation a small boreal catchment in central Sweden was studied for two years before and two years after treatment with the maximum recommended dose, 3 tonnes/ha, of crushed, self-hardened wood ash. The sampling area was situated in a slope towards a stream, to include the effect on both recharge- and discharge areas with different soil constitutions. The soil solution chemistry, exchangeable pool of cations and potential heavy metal accumulation in berries were studied. Temporary increases in soil solution concentration were found for K in the recharge area and Ca and SO4 in the discharge area when comparing ashed and control areas. No change in exchangeable cations was observed during the study period, and no increase of heavy metals in bilberries did occur. These small changes in the constitution of the soil solution do not suggest wood ash application as a method to improve soil quality in an initial phase.

  • 10.
    Norström, Sara H
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Vestin, Jenny LK
    Swedish geotechnical institute.
    Bylund, Dan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Lundström, Ulla S
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Influences of dissolved organic carbon on stream water chemistry in two forested catchments in central Sweden2010In: Biogeochemistry, ISSN 0168-2563, E-ISSN 1573-515X, Vol. 101, no 1-3, p. 229-241Article in journal (Refereed)
    Abstract [en]

    Stream water chemistry in two headwater streams draining two small, adjacent catchments in Bispgården, central Sweden was studied during the 2003 and 2004 growing seasons. The two catchments closely resemble each other in regard to size, shape and drainage density, with the major difference found in the area of wetland lining the streambeds. The emphasis of the study was to investigate the stream water chemistry of these closely resembling catchments, regarding the quality and quantity of dissolved organic carbon (DOC) and its influence on the concentrations of di- and trivalent cations. The streams showed significant differences in the content and size distribution of DOC and in the distribution of cations between the different size fractions. For both streams the high flow events induced by precipitation influenced the chemistry of the streams through increase of organic matter and its associated cations. Fanbergsbäcken, with relatively low pH and high DOC concentration, had a greater amount of high molecular mass (HMM) DOC to which approximately 75% of Al and Fe and about 50% of Ca and Mg were associated. Gråbergsbäcken, with a higher pH and lower DOC level, had approximately 65% of Al, 40% of Fe and 30% of Ca and Mg associated to its HMM DOC fraction. Sixteen different low molecular mass organic acids were found in the stream water, of which oxalic and lactic acid were present in the highest concentrations.

  • 11.
    Olofsson, Madelen
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Norström, Sara
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Bylund, Dan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Evaluation of sampling and sample preparation procedures for the determination of aromatic acids and their distribution in a podzol soil using liquid chromatography-tandem mass spectrometry2014In: Geoderma, ISSN 0016-7061, E-ISSN 1872-6259, Vol. 232-234, p. 373-380Article in journal (Refereed)
    Abstract [en]

    In this work the distribution of free and weekly adsorbed aromatic acids (phthalic acid and ten phenolicacids; gallic, p-hydroxybenzoic, salicylic, vanillic, protocatechuic, p-coumaric, syringic, sinapic, ferulic and caffeicacid), which could participate in weathering and soil formation processes, were studied for O, E and Bhorizons in a podzol soil in central Sweden. For the analysis a simple and rapid quantitative and qualitative liquidchromatography–tandem mass spectrometry method (using gradient elution) was developed with LODs rangingfrom 5 to 25 nM. Different soil solution sampling techniques (tension-lysimeter and soil centrifugation) and soilextraction with either 10 mM phosphate buffer (pH 7.2) or 50:50 (v/v) 10 mM phosphate buffer:MeOHwere compared. All eleven acids were found in detectable or trace concentrations. The most abundant aromaticacids were vanillic and phthalic acid with concentrations around 1 μM for O and E horizon respectively.Lysimeter samples resulted in the lowest concentrations followed by centrifugation samples. Ingeneral, buffer:MeOH extraction resulted in the highest concentrations for the O horizon, likely due toMeOH's ability to compete for hydrophobic sites on soil organic matter (SOM). Then again, pure bufferwith its higher ion strength, interfering with the acids electrostatic interactions with clay particles, leads tohigher extracted concentrations for the E and B horizons. Since the efficiency of the extraction solutions, to alarge extent, depends on the sample properties, a general approach is hard to appoint. However, the extractionof substituted cinnamic acids is in general facilitated by adding MeOH to the extraction solution. The use of statisticalmethods for the evaluation of the results showed a large and significant difference in aromatic acid concentrationsreceived using different sampling techniques and sample preparations. In fact, sampling methodsresulted in higher variations in aromatic acid concentrations than sampled horizon.

  • 12.
    Vestin, Jenny L. K.
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Norström, Sara H
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Bylund, Dan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Lundström, Ulla S
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Soil solution and stream water chemistry in a forested catchment II: Influence of organic matter2008In: Geoderma, ISSN 0016-7061, E-ISSN 1872-6259, Vol. 144, no 2008, p. 271-278Article in journal (Refereed)
    Abstract [en]

    Differences between recharge and discharge areas in soil forming processes and nutrient conditions were observed in an earlier study of a catchment area in central Sweden (63°07′N, 16°70′E; Vestin, J.L.K., Norström, S.H., Bylund, D., Mellander, P-E., Lundström, U.S., submitted for publication to Geoderma. Soil solution and stream water chemistry in a forested catchment, I Dynamics.). To further examine the factors that determine the soil and stream water properties in the catchment area, the present study focused on the organic dynamics and the association of cations to different size fractions of organic matter. Six sampling plots were established in each of the recharge and discharge areas, respectively, with samples taken in June 2004. Dissolved organic carbon (DOC) and cation concentrations in the soil solution and stream water were determined. In the recharge area, low molecular mass (LMM) organics played an important role in transportation of several cations through the soil profile, inducing the podzolisation process by associating with Al and Fe. In the discharge area close to the stream, high molecular mass (HMM) organics appeared to play a crucial role in transportation of cations. Here the majority of recovered cations were associated with HMM organic matter, inhibiting the podzolisation process. The total concentration of C and DOC was higher than in the recharge area, and the concentration of cations increased with depth in the mineral soil. In the stream water, as in the discharge area soil solution, all carboxylic groups were associated to cations. Both Al and Fe were completely associated with the HMM DOC fraction, which indicated a rapid turnover of LMM DOC in stream water. Thus we conclude that DOC plays an important role in soil forming processes, and that its different size fractions have large effects on the transportation of elements in different soils and in stream water.

  • 13.
    Vestin, Jenny L. K.
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Norström, Sara H
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Bylund, Dan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Mellander, Per-Erik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Lundström, Ulla S
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Soil solution and stream water chemistry in a forested catchment I: Dynamics2008In: Geoderma, ISSN 0016-7061, E-ISSN 1872-6259, Vol. 144, no 1/2, p. 256-270Article in journal (Refereed)
    Abstract [en]

    Soil solution and stream water chemistry were studied during two years in a catchment in Bispgården in central Sweden (63°07′N, 16°70′E). Soil samples and soil solution were collected in a slope at two distances (10 and 80 m) from a stream. The aims were to examine interactions between recharge (podzol) and discharge (arenosol) areas and to investigate the relations between soil solution and stream water chemistry. The parent material was similar within the catchment, but the content of C and N were higher in the discharge area most likely due to the difference in hydrological conditions compared to the recharge area. Exchangeable cations and base saturation were higher in the discharge area than in the recharge area, which may be due to the higher content of C. The concentrations in soil solution of H, DOC, NO3, SO4, Al, Si, Ca and K charge area compared to the recharge area which was probably caused by transportation of elements in soil and retention due to the increased content of C. During snow melt, the concentrations in soil solution of DOC, SO4, Al, Si, Ca and K were low due to dilution and low biological activity. The concentrations were then increasing during the seasons as an effect of biological activity and mineral weathering. NO3 concentration in soil solution was found in higher concentrations during snow melting and was then diminishing during summer likely as a result of biological uptake. After a dry period followed by an intensive rain in August 2003, the stream water chemistry was markedly altered for a few days. The concentrations of H, DOC SO4, Al and Ca were increased and the concentration of Si was decreased in the stream water. It therefore appeared that the stream water mirrored the upper soil horizons in the discharge area during high flows, while reflecting the lower soil horizons and ground water during low flows.

  • 14.
    Vilches, Ana Paola
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Gallampois, Christine
    Olofsson, Madelen A.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Norström, Sara H.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Fransson, Petra
    Bylund, Dan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Effects of bio-ash on the exudation pattern of eight ectomycorrhizal fungi - an untargeted metabolomic studyManuscript (preprint) (Other academic)
  • 15.
    Vilches, Ana Paola
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Norström, Sara H
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Bylund, Dan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Direct analysis of free amino acids by mixed-mode chromatography with tandem mass spectrometry2017In: Journal of Separation Science, ISSN 1615-9306, E-ISSN 1615-9314, Vol. 40, no 7, p. 1482-1492Article in journal (Refereed)
    Abstract [en]

    We developed a straightforward, robust, and relatively fast method for the analysis of amino acids by mixed-mode high-performance liquid chromatography coupled to electrospray ionization tandem mass spectrometry. The method does not involve derivatization and allows the detection of 21 amino acids, representing a wide range of isoelectric points, in less than 40 min. Chromatographic separation was governed by a silica-based mixed-mode column providing simultaneous hydrophobic and ion exchange separation mechanisms. The use of tandem mass spectrometry increased selectivity, reducing potential problems associated with poor selectivity in the chromatographic system. For an injection volume of 1 μL, we obtained detection limits <3 μM for the majority of analytes. For all analytes, a linearity of r > 0.99 was obtained, recovery in matrix was >86%, and the retention times were highly reproducible. The method was successfully applied to soil solution and fungal culture samples, demonstrating the advantages in successfully avoiding issues associated with high amounts of substances that may interfere with derivatization-based methods. This method represents an alternative to derivatization-based methods and can be applied in areas where sample matrices are highly complex.

  • 16.
    Vilches, Ana Paola
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Norström, Sara
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Olofsson, Madelen
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Fransson, Petra
    Swedish University of Agricultural Sciences, Uppsala.
    Bylund, Dan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Biofuel ash addition increases ectomycorrhizal fungal exudation in pure culture2018In: Environmental Chemistry, ISSN 1448-2517, E-ISSN 1449-8979, Vol. 15, no 8, p. 481-492Article in journal (Refereed)
    Abstract [en]

    Environmental context. Spreading recycled wood ash in forests may counteract acidification and nutrient losses, but the process may also affect symbiotic fungi in these eco-systems. We show how fungal species react when exposed to ash solutions; for example, by an increased release of organic acids and other compounds. These effects can influence pH and metal availability in forest soils treated with ash.. Recycling of wood ash may counteract acidification and losses of base cations resulting from whole-tree harvesting in boreal forest ecosystems. The effects of ash treatment on growth and exudation of eight ectomycorrhizal fungal species were investigated in this study. Six basidiomycetes and two ascomycetes were grown in liquid pure culture with different levels of ash amendments. Biomass production, pH and the exudation of 17 low-molecular-mass organic acids (LMMOAs), 23 amino acids (AAs) and 9 hydroxamate siderophores (HSs) were recorded after 1, 2 and 4 weeks of incubation. Ash did not affect fungal growth, but resulted in higher exudation of the investigated compounds, in particular LMMOAs. Ash also influenced the composition of the exudates. We measured exudation of LMMOAs and AAs up to millimolar and micromolar concentrations respectively. For example, Rhizopogon roseolus mainly produced oxalic acid, whereas Lactarius rufus and Tomentellopsis submollis produced the highest concentrations of AAs. Ferricrocin, the only HS detected, was exuded at the nanomolar level. Exudation responses were also highly species-dependent, e.g. the ascomycetous isolates that produced the largest biomass released low amounts of exudates compared with the basidiomycetes, and were the only ones producing siderophores. This growth–exudation response to ash is likely a trade-off in carbon allocation whereby the mycorrhizal fungal species invest carbon in either higher biomass production or higher exudation.

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