Hydrodynamic radius determination with asymmetrical flow field-flow fractionation using decaying cross-flows. Part II. Experimental evaluation

Magnusson, Emma; Håkansson, Andréas; Janiak, John; Bergenståhl, Björn; Nilsson, Lars

doi:10.1016/j.chroma.2012.07.005

Cited by 43 publications

(18 citation statements)

References 20 publications

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“…With a constant V c in the elution step one can evaluate the hydrodynamic diameter of a colloid, d H , from the retention ratio, R, dened as a ratio of the retention time (t r ) to the void time (t 0 ), which is the elution time of a nonretained component such as sodium azide. 26,31 In this study we adapted the gradient cross ow method, 27,28 where V c is decreased over time in order to extend the fractionation range in a given experimental time without a large loss of resolution for relatively smaller sizes. V c was quadratically decreased as a function of time, t, in the form V c ¼ 0.9(t À 30) 2 /900 for the granitic groundwater, and V c ¼ 1.…”

Section: Fl-fff-icp-ms Measurementsmentioning

confidence: 99%

“…In our previous study colloids in a limited range of size of the granitic groundwater were examined. 19 We have extended it by using the gradient cross ow technique 27,28 and measuring even larger colloids appearing in the washing step to determine the similarities and differences in the size distribution and compositions of colloids in both the groundwater samples over a wide size range. The comparison of these groundwater samples is of great importance, as their geological settings are potential candidates of repository sites in geological disposal programs of many countries.…”

Section: Introductionmentioning

confidence: 99%

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Comparative study of granitic and sedimentary groundwater colloids by flow-field flow fractionation coupled with ICP-MS

Saito

Hamamoto

Mizuno

et al. 2015

J. Anal. At. Spectrom.

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Section: Fl-fff-icp-ms Measurementsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Comparative study of granitic and sedimentary groundwater colloids by flow-field flow fractionation coupled with ICP-MS

Saito

Hamamoto

Mizuno

et al. 2015

J. Anal. At. Spectrom.

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“…The calculation of the diffusion coefficient from the elution time becomes more complex if the cross-flow changes during elution. A numerical solution was therefore developed for trapezoidal channel and was improved for cross-flow decaying with the time [170][171][172].…”

Section: Separation Principlementioning

confidence: 99%

Size Separation Techniques for the Characterisation of Cross-Linked Casein: A Review of Methods and Their Applications

et al. 2018

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Abstract:Casein is the major protein fraction in milk, and its cross-linking has been a topic of scientific interest for many years. Enzymatic cross-linking has huge potential to modify relevant techno-functional properties of casein, whereas non-enzymatic cross-linking occurs naturally during the storage and processing of milk and dairy products. Two size separation techniques were applied for characterisation of these reactions: gel electrophoresis and size exclusion chromatography. This review summarises their separation principles and discusses the outcome of studies on cross-linked casein from the last~20 years. Both methods, however, show limitations concerning separation range and are applied mainly under denaturing and reducing conditions. In contrast, field flow fractionation has a broad separation range and can be easily applied under native conditions. Although this method has become a powerful tool in polymer and nanoparticle analysis and was used in few studies on casein micelles, it has not yet been applied to investigate cross-linked casein. Finally, the principles and requirements for absolute molar mass determination are reviewed, which will be of increased interest in the future since suitable calibration substances for casein polymers are scarce.

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“…The radius of gyration ( r g ) of the dimer and the hexamer of the Lb GadB could not be measured by MALS as the analytes behaved as isotropic scatterers, and hence, no angular dependence in the scattered light is observed. The d H was determined using AF4 theory [ 23 , 24 ] and were compared with results obtained from molecular modeling for the dimer and the hexamer of Lb GadB. From the AF4 theory, the d H of the dimer and the hexamer of Lb GadB were determined to be 6 and 10 nm, respectively, and were in reasonable agreement with those from molecular modeling, which were 6.4 × 7.6 nm for the dimer and 7.6 × 13.1 nm for the hexamer.…”

Section: Resultsmentioning

confidence: 99%

“…In all cases, the Berry method was used to fit the light scattering data [ 21 , 22 ]. From AF4 retention time, the hydrodynamic diameter ( d H ) of a sample was calculated by the AF4 theory using the FFFHydRad 2.0 software [ 23 , 24 ].…”

Section: Methodsmentioning

confidence: 99%

Study on oligomerization of glutamate decarboxylase from Lactobacillus brevis using asymmetrical flow field-flow fractionation (AF4) with light scattering techniques

et al. 2017

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In this work, asymmetrical flow field-flow fractionation (AF4) coupled with UV/Vis, multi-angle light scattering (MALS), and differential refractive index (dRI) detectors (AF4-UV-MALS-dRI) was employed for analysis of glutamate decarboxylase (LbGadB) from Lactobacillus brevis (L. brevis). AF4 provided molecular weight (MW) (or size)-based separation of dimer, hexamer, and aggregates of LbGadB. The effect of pH on oligomerization of LbGadB was investigated, and then AF4 results were compared to those from molecular modeling. The MWs measured by AF4-UV-MALS-dRI for dimeric and hexameric forms of LbGadB were 110 and 350 kDa, respectively, which are in good agreements with those theoretically calculated (110 and 330 kDa). The molecular sizes determined by AF4-UV-MALS-dRI were also in good agreement with those obtained from molecular modeling (6 and 10 nm, respectively, for dimeric and hexameric from AF4-UV-MALS-dRI and 6.4 × 7.6 and 7.6 × 13.1 nm from molecular modeling). The effects of temperature, salt type, and salt concentration on oligomerization of LbGadB were also investigated using dynamic light scattering (DLS). It was found that the hexameric form of LbGadB was most stable at pH 6 and in presence of NaCl or KCl. The results indicate that AF4, in combination of various online detectors mentioned above, provides an effective tool for monitoring of oligomerization of LbGadB under different conditions, such as temperature, pH, type of salts, and salt concentrations.Electronic supplementary materialThe online version of this article (10.1007/s00216-017-0735-6) contains supplementary material, which is available to authorized users.

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Hydrodynamic radius determination with asymmetrical flow field-flow fractionation using decaying cross-flows. Part II. Experimental evaluation

Cited by 43 publications

References 20 publications

Comparative study of granitic and sedimentary groundwater colloids by flow-field flow fractionation coupled with ICP-MS

Comparative study of granitic and sedimentary groundwater colloids by flow-field flow fractionation coupled with ICP-MS

Size Separation Techniques for the Characterisation of Cross-Linked Casein: A Review of Methods and Their Applications

Study on oligomerization of glutamate decarboxylase from Lactobacillus brevis using asymmetrical flow field-flow fractionation (AF4) with light scattering techniques

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