Browsing by Subject "Separation"

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  • Takala, Ninni; Siren, Heli; Jakl, Michal; Dytrtová, Jana Jaklová (2019)
    The azoles (represented by penconazole, cyproconazole, and tebuconazole in this study) are frequently used agrochemicals to protect various crops against mildew and fungi. They are considered as endocrine disruptors, because they block the biosynthesis (on the level of enzymes inhibition) of biochemicals with steroid structure. Besides targeted impacts, they can partly get into the soil with the rainfall or litter fall and influence/block the biosynthesis of sterols of non-target organisms. In this sense, the risk of disruption of rhizosphere plant-microbial symbiosis and dynamic processes in the soil solution by azoles is of high importance to be evaluated. We have developed an analytical methodology for determination of penconazole, cyproconazole, and tebuconazole in soil solution using capillary electrophoresis with a photodiode array detector at UV-214 nm and acidic electrolyte solution (pH 1.48). The results were also compared with mass spectrometric measurements using mu-TOF mass spectrometry. There approx. 90% of present azoles were bound in the soil solution matrix. The detection limit for these azoles is about 10(-7) mol dm(-3). Because of very low pK(a) of azoles, we have to consider deprotonation of azoles and consequently the high affinity to create complexes with cations. The majority of present azoles in soil solution might form neutral adducts with mono-cations, making them invisible in electrospray mass spectra. [GRAPHICS] .
  • Tenkanen, Maija; Pitkänen, Leena (2019)
    The asymmetric flow field-flow fractionation (AF4) method was developed for cationic cellulose derivatives. AF4 is the method of choice especially for high-molar mass samples, which are challenging to characterize with conventional chromatographic techniques such as size-exclusion chromatography (SEC). The cationic charge of macromolecules also complicates the size-based separations where no interaction between the analytes and the column stationary phase (SEC) or membrane (AF4) should occur. However, many column matrices and membranes carry negative charge and thus preventing interactions between cationic analytes and negatively charged separation support should be taken into consideration when doing method development. In this study, two eluent compositions, neutral and acidic, were tested for AF4 separation of cationic hydroxyethyl celluloses with varying charge densities. The eluent composition with a pH below the isoelectric point of regenerated cellulose membrane, which was used in this AF4 study, enabled the size-based separation with close to 100% analysis recovery. Macromolecular parameters (molar mass and radius of gyration) and conformation were investigated by coupling a multi-angle light scattering detector and differential refractometer to the AF4 system.
  • Liangsupree, Thanaporn; Multia, Evgen; Riekkola, Marja-Liisa (2021)
    Extracellular vesicles (EVs) are heterogenous membrane-bound vesicles released from various origins. EVs play a crucial role in cellular communication and mediate several physiological and pathological processes, highlighting their potential therapeutic and diagnostic applications. Due to the rapid increase in interests and needs to elucidate EV properties and functions, numerous isolation and separation approaches for EVs have been developed to overcome limitations of conventional techniques, such as ultracentrifugation. This review focuses on recently emerging and modern EV isolation and separation techniques, including size-, charge-, and affinity-based techniques while excluding ultracentrifugation and precipitation-based techniques due to their multiple limitations. The advantages and drawbacks of each technique are discussed together with insights into their applications. Emerging approaches all share similar features in terms of being time-effective, easy-to-operate, and capable of providing EVs with suitable and desirable purity and integrity for applications of interest. Combination and hyphenation of techniques have been used for EV isolation and separation to yield EVs with the best quality. The most recent development using an automated on-line system including selective affinity-based trapping unit and asymmetrical flow field-flow fractionation allows reliable isolation and fractionation of EV subpopulations from human plasma. (C) 2020 The Author(s). Published by Elsevier B.V.
  • Bjerregaard, .; Charalampidis, A.; Frøding, R.; Shetty, R.; Pastell, H.; Jacobsen, C.; Zhuang, S.; Pinelo, M.; Hansen, P.; Hobley, T. (2019)
    European Food Research and Technology Vol. 245, No. 3, pp. 545 - 558
    Very large amounts of brewer’s spent grains (BSG) are produced in the world which is usually considered as a waste, or animal feed, rather than food for humans. Here, we report, for the first time, a new process at pilot scale for the separation of brewer’s spent grain and trub to solid and liquid streams that can be used in foods. A new type of continuous rotary drum press was used to process hot BSG to produce a liquid filtrate and a filter cake stream. Analysis showed that of the starting mass of BSG (ca. 120 kg), the liquid filtrate composed 50% of the mass, and the filter cake fraction composed 50% of the mass. The dry weight (DW) content of the BSG increased from 23 to over 35%. This led to concentration of insoluble dietary fibre (from 38 to 54%) and phenolics in the filter cake (from 102 to 150 mg/100 g DW as gallic acid equivalents). No fractionation of soluble species such as proteins occurred. Centrifugation of the filtrate from the rotary drum press led to a clarified supernatant stream and a paste. Concentration of insoluble dietary fibre and phenolics occurred in the paste (from 5 to 14% of DW and 61 to 114 mg/100 g DW as gallic acid equivalents), whereas soluble fibre and protein did not selectively partition. Given that the unit operations used here are scaleable and approved for food production, an industrially feasible route now exists to process brewers spent grains to ingredients.
  • Salonen, Minna K.; von Bonsdorff, Mikaela B.; Kautiainen, Hannu; von Bonsdorff, Monika E.; Kajantie, Eero; Wasenius, Niko S.; Pesonen, Anukatriina; Raikkonen, Katri; Eriksson, Johan G. (2019)
    Introduction: Traumatic experiences, such as separation from parents in childhood causing early life stress (ELS) may increase the risk of adverse long-term health outcomes and biological age-related changes. This may have an impact on work career. Our aim was to examine long term consequences of ELS due to temporary separation from parents during World War II (WWII) in relation to work career. Material and methods: The Helsinki Birth Cohort Study comprises 13,345 individuals born in Helsinki, Finland, between the years 1934-1944. From the original cohort, 1781 individuals were identified as being separated temporarily from their parents due to World War II. Information on date and type of pension was provided by the Finnish Centre for Pensions and the Social Insurance Institution of Finland. The cohort members either transitioned into old age pension at the statutory retirement age or retired earlier and transitioned into disability, unemployment, part-time pension or died before retirement. Results: Those who were separated were more likely to have transitioned into disability pension (RRR: 1.26: 95% CI: 1.06-1.48), especially due to diseases of the musculoskeletal system (OR: 1.57; 95% CI: 1.20-2.07), or into unemployment pension (RRR: 1.25; 95% CI: 1.02-1.53) compared with those not separated from their parents. Longer duration of separation was associated with early exit from the workforce compared with non-separation. Conclusions: Exposure to ELS may have an impact upon lifetime work career. Early interventions preventing exposure to ELS or mitigating its negative effects may prolong future work careers along with healthier aging across the life-span.