Dataset Information

High-Resolution Asymmetrical Flow Field-Flow Fractionation Data Evaluation via Richardson-Lucy-Based Fractogram Correction.

ABSTRACT: Asymmetrical flow field-flow fractionation (AF4) is a chromatographic separation technique that can be used for a broad range of particles or macromolecules. As an orthogonal method to size exclusion chromatography (SEC) with a much broader separation size range (1-800 nm) AF4 is gaining importance. However, the data evaluation capacities are far behind in comparison to other techniques like analytical ultracentrifugation (AUC). A program for evaluation of data from AF4 with a coupled multiangle laser light scattering (MALLS) detector was developed that allows the determination of the distributions of diffusion coefficients ( D), hydrodynamic radii ( Rh), molecular weights ( Mw), and relative concentrations (RC) of the obtained species. In addition, two algorithms to remove broadening effects via deconvolution were implemented and tested for their validity. The first is an extension of the known diffusion broadening correction applying the entire diffusion coefficient distribution instead of a single diffusion coefficient. The second applies the Richardson-Lucy algorithm for the deconvolution of overlapping signals from stars in astronomy. This program allows a reproducible strong enhancement of the fractogram resolution allowing for entire baseline separations of proteins. The comparison of the values for Mw determined by a partial Zimm plot from each data point of the original fractogram and the deconvolved results shows that especially the Richardson-Lucy algorithm maintains a high degree of data robustness.

SUBMITTER: Schmid M

PROVIDER: S-EPMC6643961 | biostudies-literature | 2018 Dec

REPOSITORIES: biostudies-literature

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Publications

High-Resolution Asymmetrical Flow Field-Flow Fractionation Data Evaluation via Richardson-Lucy-Based Fractogram Correction.

Schmid Marius M Häusele Benedikt B Junk Michael M Brookes Emre E Frank Jürgen J Cölfen Helmut H

Analytical chemistry 20181113 23

Asymmetrical flow field-flow fractionation (AF4) is a chromatographic separation technique that can be used for a broad range of particles or macromolecules. As an orthogonal method to size exclusion chromatography (SEC) with a much broader separation size range (1-800 nm) AF4 is gaining importance. However, the data evaluation capacities are far behind in comparison to other techniques like analytical ultracentrifugation (AUC). A program for evaluation of data from AF4 with a coupled multiangle ...[more]

PMID: 30376711

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Project description:Cellulose nanocrystals (CNCs) are renewable, naturally derived polymeric nanomaterials receiving substantial attention for a wide range of potential applications. The recent availability of high quality reference materials will facilitate the development and validation of measurement methods needed to advance the scientific and commercial use of CNCs. In the present study, we demonstrate an optimized method to fractionate CNCs with narrow size dispersion based on asymmetrical-flow field-flow fractionation (AF4) coupled with on-line multi-angle light scattering (MALS), dynamic light scattering (DLS), and differential refractometry (dRI). A stable suspension of CNC (Certified Reference Material CNCD-1, National Research Council-Canada) in deionized water was prepared using a dispersion method provided by NRC and adopted from a protocol originally developed at the National Institute of Standards and Technology. The as-prepared material was initially characterized in batch mode to validate the NRC dispersion method. AF4 was then optimized for channel and cross flow, mobile phase composition, and injection volume, among other parameters. Additionally, suspensions containing (1.25-10) mg mL-1 CNC were injected directly into the dRI detector (off-line), yielding a dn/dc value of 0.148 ± 0.003 mL g-1. dRI was then used as an on-line mass sensitive detector to quantify recovery. Results show that maximum recovery (? 99%) was achieved under optimized conditions. The weight-averaged molar mass (Mw) was estimated at roughly 107 Da from a partial Zimm analysis. The optical radius of gyration, Rg, and the hydrodynamic radius, Rh, were measured during elution. The shape factor (Rg/Rh) ranged from 1.5 to 1.9 for the fractionated material, supporting an elongated or rod-like structure. To our knowledge, this is the first time that both the morphology and molar mass of CNCs have been directly measured for the full distribution of species. Finally, we developed and demonstrated a semi-preparatory fractionation method to separate CNCs at the milligram scale for off-line research and analysis.

Dataset Information

High-Resolution Asymmetrical Flow Field-Flow Fractionation Data Evaluation via Richardson-Lucy-Based Fractogram Correction.

Publications

High-Resolution Asymmetrical Flow Field-Flow Fractionation Data Evaluation via Richardson-Lucy-Based Fractogram Correction.

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