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- Fuentes, Catalina, et al.
(författare)
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Fractionation and characterization of starch granules using field-flow fractionation (FFF) and differential scanning calorimetry (DSC)
- 2019
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Ingår i: Analytical and Bioanalytical Chemistry. - : Springer Science and Business Media LLC. - 1618-2642 .- 1618-2650. ; 411:16, s. 3665-3674
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Tidskriftsartikel (refereegranskat)abstract
- Starch is one of the main carbohydrates in food; it is formed by two polysaccharides: amylose and amylopectin. The granule size of starch varies with different botanical origins and ranges from less than 1 μm to more than 100 μm. Some physicochemical and functional properties vary with the size of the granule, which makes it of great interest to find an efficient and accurate size-based separation method. In this study, the full-feed depletion mode of split-flow thin cell fractionation (FFD-SF) was employed for a size-based fractionation of two types of starch granules (corn and potato) on a large scale. The fractionation efficiency (FE) of fraction-a for corn and potato granules was 98.4 and 99.4%, respectively. The FFD-SF fractions were analyzed using optical microscopy (OM) and gravitational field-flow fractionation (GrFFF). The respective size distribution results were in close agreement for the corn starch fractions, while they were slightly different for the potato starch fractions. The thermal properties of FFD-SF fractions were analyzed, and the results for the potato starch showed that the peak temperature of gelatinization (T p ) slightly decreases as the size of the granules increases. Additionally, the enthalpy of gelatinization (ΔH) increases when the granule size increases and shows negative correlation with the gelatinization range (ΔT).
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| 2. |
- Lee, Jangjae, et al.
(författare)
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Synthesis and characterization of elution behavior of nonspherical gold nanoparticles in asymmetrical flow field-flow fractionation (AsFlFFF)
- 2020
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Ingår i: Journal of Nanoparticle Research. - : Springer Science and Business Media LLC. - 1388-0764 .- 1572-896X. ; 22:9
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Tidskriftsartikel (refereegranskat)abstract
- Asymmetrical flow FFF (AsFlFFF) is a member of field-flow fractionation (FFF) and can provide the separation of particles with size from nano to microscale based on their hydrodynamic diameters with smaller particles being eluted earlier than larger ones. For spheres, if the AsFlFFF conditions are well optimized, the FFF theory allows prediction of the elution time for a given diameter. Herein, we aim to use the AsFlFFF channel to compare the elution behavior of the gold nanoparticles with three different morphologies and give a comprehensive depiction for the mechanism of their separation in AsFlFFF. Furthermore, the particles size obtained from AsFlFFF was compared with that obtained from other techniques such as transmission electron microscopy (TEM), and dynamic light scattering. In this study, gold nanospheres (GNS), gold nanotriangles (GNT), and gold nanorods (GNR) were synthesized. TEM data stated that the mean particle diameter and the edge length of GNS and GNT were 51 and 35 nm, respectively, and the length of GNR was 47 nm. Although, the diameter of GNS is close to the length of GNR, the elution time of GNS (4.45 min) was much longer than that of the GNR (3.70 min) at the same AsFlFFF conditions. Also, the elution time of GNT was longer than that of GNR, even though it has smaller size than GNR. This might be attributed to GNR reaching an equilibrium position that is farther away from the accumulation wall of the channel than GNS, resulting in earlier elution than GNS. The GNT particles are rather similar in shape to spheres, and may behave more closely to the spheres than GNR. It seem that AsFlFFF could be an analytical technique for particle size analysis and separation of nanoparticles of different shapes.
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