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  • 1.
    Bak, Søren Alex
    et al.
    Eurofins Denmark A/S, Environment, Vejen.
    Hansen, Martin
    Department of Civil & Environmental Engineering, Stanford University.
    Pedersen, Kenneth Munk
    Halling-Sørensen, Bent
    Björklund, Erland
    Kristianstad University, School of Education and Environment, Avdelningen för Naturvetenskap. Kristianstad University, Plattformen för molekylär analys. Kristianstad University, Faculty of Natural Science, Avdelningen för miljö- och biovetenskap. Kristianstad University, Faculty of Natural Science, Research environment MoLab.
    Quantification of four ionophores in soil, sediment and manure using pressurised liquid extraction2013In: Journal of Chromatography A, ISSN 0021-9673, E-ISSN 1873-3778, Vol. 1307, no September, p. 27-33Article in journal (Refereed)
    Abstract [en]

    A multi-residue pressurised liquid extraction (PLE) methodology has been established for the determination of the four ionophores: lasalocid, monensin, salinomycin and narasin in solid environmental matrices. The PLE methodology is combined with solid phase extraction as clean-up using liquid chromatography coupled to tandem mass spectrometry applying electrospray ionisation for detection. The samples were freeze-dried prior to extraction. The absolute recoveries for soil and sediment ranged from 71 to 123% (relative standard deviation (RSDs) below 16%) and in the range 94–133% (RSDs 9–35%) for poultry manure. The final method allowed for the detection of four ionophores down to a few hundred ng kg−1 in natural solid matrices with limit of quantifications (LOQs) being 0.96, 0.87, 0.98, and 0.64 μg kg−1 in soil for lasalocid, monensin, salinomycin, and narasin, respectively. Corresponding LOQs in sediment were 1.28, 1.34, 1.39, and 0.78 μg kg−1 for the respective ionophores, while in manure the LOQs were 0.98, 1.01, 1.45, and 1.01 μg kg−1.

  • 2.
    Håkansson, Andreas
    et al.
    Kristianstad University, School of Education and Environment, Avdelningen för Praktisk-estetiska ämnen. Lunds universitet.
    Magnusson, Emma
    Bergenståhl, Björn
    Nilsson, Lars
    Hydrodynamic radius determination with asymmetrical flow field-flow fractionation using decaying cross-flows: Part I. A theoretical approach2012In: Journal of Chromatography A, ISSN 0021-9673, E-ISSN 1873-3778, Vol. 1253, p. 120-126Article in journal (Refereed)
    Abstract [en]

    Direct determination of hydrodynamic radius from retention time is an advantage of the field-flow fractionation techniques. However, this is not always completely straight forward since non-idealities exist and assumptions have been made in deriving the retention equations. In this study we investigate the effect on accuracy from two factors: (1) level of sophistication of the equations used to determine channel height from a calibration experiment and (2) the influence of secondary relaxation on the accuracy of hydrodynamic radius determination. A new improved technique for estimating the channel height from calibration experiments is suggested. It is concluded that severe systematic error can arise if the most common channel height equations are used and an alternative more rigorous approach is described. For secondary relaxation it is concluded that this effect increases with the cross-flow decay rate. The secondary relaxation effect is quantified for different conditions. This is part one of two. In the second part the determination of hydrodynamic radius are evaluated experimentally under similar conditions.

  • 3. Magnusson, Emma
    et al.
    Håkansson, Andreas
    Kristianstad University, School of Education and Environment, Avdelningen för Praktisk-estetiska ämnen.
    Janiak, John
    Bergenståhl, Björn
    Nilsson, Lars
    Hydrodynamic radius determination with asymmetrical flow field-flow fractionation using decaying cross-flows: Part II. Experimental evaluation2012In: Journal of Chromatography A, ISSN 0021-9673, E-ISSN 1873-3778, Vol. 1253, p. 127-133Article in journal (Refereed)
    Abstract [en]

    In this study we investigate the effect of programmed cross-flows on the error in the hydrodynamic radii (rh) determination with asymmetrical flow field-flow fractionation (AsFlFFF). Three different standard polystyrene particles (nominal radii of 30 and 40 and 50 nm) are fractionated with exponentially and linearly decaying cross-flows with different decay rates. Hydrodynamic radii are calculated according to retention theory including steric effects. Rapid decay is expected to give rise to systematic deviations in rh determination. The error in rh was found to be small when decay rates with half-lives longer than 6 min were used, whereas steeper decays could give rise to errors as high as 16% of the particle size. The error is often explained in terms of secondary relaxation. However, comparisons show that experimental errors are significantly larger than what would be expected due to secondary relaxation, suggesting that other factors also have to be considered in order to fully understand deviations for rapidly decaying cross-flow.

  • 4.
    Svahn, Ola
    et al.
    Kristianstad University, School of Education and Environment, Avdelningen för Naturvetenskap. Kristianstad University, Plattformen för molekylär analys. Kristianstad University, Faculty of Natural Science, Research environment MoLab.
    Björklund, Erland
    Kristianstad University, School of Education and Environment, Avdelningen för Naturvetenskap. Kristianstad University, Plattformen för molekylär analys. Kristianstad University, Faculty of Natural Science, Avdelningen för miljö- och biovetenskap. Kristianstad University, Faculty of Natural Science, Research environment MoLab.
    Describing sorption of pharmaceuticals to lake and river sediments, and sewage sludge from UNESCO Biosphere Reserve Kristianstads Vattenrike by chromatographic asymmetry factors and recovery measurements2015In: Journal of Chromatography A, ISSN 0021-9673, E-ISSN 1873-3778, Vol. 415, p. 73-82Article in journal (Refereed)
    Abstract [en]

    Over the past 30 years a vast number of studies have demonstrated the presence of pharmaceutical residues in the environment. But still knowledge is scarce regarding the interaction of these emerging pollutants with various matrices in nature. A chromatographic system with on-line detection was developed to perform a sorption study of six selected pharmaceuticals to four natural sediments and dewatered digested sewage treatment plant sludge with differing physicochemical characteristics. Sorption effects, measured as asymmetry factors and recoveries, differed pronouncedly among the pharmaceuticals and between the matrices, which could be explained by basic physicochemical properties of the investigated compounds in relation to matrix characteristics. Protonated and deprotonated molecular properties had the greatest importance for sorbate–sorbent interactions. Atenolol, with cationic properties, showed the highest degree of sorption regardless of the matrix studied. Diclofenac and furosemide, both acids, showed the least tendency towards interactions to natural matrices. Among the neutral compounds bendroflumethiazide, carbamazepine and oxazepam, weaker forces, such as van der Waals, aromatic electron donor–acceptor interactions, and hydrogen forces, seemed more important to determine sorption differences. Results revealed that sorption of pharmaceuticals on natural sediments decreased in the order: atenolol (+) > bendroflumethiazide > oxazepam > carbamazepine > diclofenac (−) > furosemide(–). The matrix content of organic matter measured as total organic carbon (TOC) clearly dictated drug sorption. Beside from studying matrix interaction, these results and the developed technique and methodology might find use in the development of new removal processes of pharmaceuticals from wastewater based on improved knowledge concerning chemical interactions to filter materials.

  • 5.
    Zorita, Saioa
    et al.
    Division of Analytical Chemistry, University of Lund.
    Hallgren, Pär
    Kristianstad University College, Department of Mathematics and Science.
    Mathiasson, Lennart
    Division of Analytical Chemistry, University of Lund.
    Steroid hormone determination in water using an environmentally friendly membrane based extraction technique2008In: Journal of Chromatography A, ISSN 0021-9673, E-ISSN 1873-3778, Vol. 1192, no 1, p. 1-8Article in journal (Refereed)
    Abstract [en]

    In this study, a method was developed for determination of steroid hormones (17beta-estradiol, estrone, 17alpha-ethynylestradiol) in tap and sewage water samples from Sweden. Sample preparation and analysis were performed by a hollow-fibre microporous membrane liquid-liquid extraction (HF-MMLLE) set-up combined with gas chromatography-mass spectrometry (GC-MS). In this approach, only the organic liquid in the lumen (10microL) of the hollow-fibre membrane was utilised for depleting extraction. Several parameters were studied, including: type of organic solvent, sample pH, salt and humic acid content. The optimised method allowed the determination of the analyte at the low ngL(-1) level in tap and sewage water. A linear plot gave correlation coefficients better than 0.995 and resulted in a method limit of detection of 1.6, 3 and 10ngL(-1) for 17beta-estradiol, estrone, and 17alpha-ethynylestradiol, respectively, in sewage water. Enrichment factors were over 1400 after derivatisation. The repeatabilities at 50 and 600ngL(-1) were better than 10% and 6%, respectively.

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