Advances in Physicochemical Properties of Biopolymers: Part 1

Martin A. Masuelli, Denis Renard, Martin A. Masuelli, Denis Renard

• Publisher: Bentham Science Publishers
• Year: 2017
• Print ISBN: 9781681084541
• eBook ISBN: 9781681084534
• Topic: Technik & Maschinenbau
• Subtopic: Werkstoffwissenschaft

The last two decades have seen a number of significant advances in the methodology for evaluating the molecular weight distributions of polydispersed macromolecular systems in solution at the molecular level. This reference presents reviews on the progress in different analytical and characterization methods of biopolymers.
Readers will find useful information about combinations of complex biopolymer analysis such as chromatographic or membrane based fractionation procedures combined with multiple detectors on line (multi-angle laser light scattering or MALLS). Key topics include:
refractive index, UV-Vis absorbance and intrinsic viscosity detection systems,
advances in SEC-MALLS (size exclusion chromatography coupled to multi-angle laser light scattering) and FFF-MALLS (field flow fractionation coupled on line to MALLS),
HPSEC-A4F-MALLS, matrix-assisted laser-desorption ionization (MALDI)
electrospray ionization (ESI) mass spectrometry
nuclear magnetic resonance (NMR) spectroscopy
This reference is intended for students of applied chemistry and biochemistry who require information about biopolymer analysis and characterization.

High-Performance Size-Exclusion Chromatography coupled with on-line Multi-angle Laser Light Scattering (HPSEC-MALLS)

Agnès Rolland-Sabaté^*

UMR408 Sécurité et Qualité des Produits d'Origine Végétale, INRA, Université Avignon, F-84000 Avignon, France; UR1268 Biopolymères Interactions Assemblages, INRA, F-44316 Nantes, France

Abstract

High-Performance Size-Exclusion Chromatography (HPSEC) is widely used for the determination of the molar mass and size distribution of biopolymers in aqueous or organic solvents. Elements of the theory of fractionation by HPSEC, column calibration and online light scattering detection are given, showing that coupling HPSEC with multi-angle laser light scattering detection makes it easier to obtain molar mass distributions since light (MALLS) scattering gives the weight-average molar mass at each elution volume of the chromatogram. Some applications of HPSEC-MALLS for the macromolecular characterization of starches, glycogens, dextrans, celluloses, hemicelluloses, β-glucans, pectins, gums, alginates, carrageenans, chitosans, lignins, proteins and peptides are also presented.

Keywords: Cellulose, Chitosan, Gum, High-Performance Size-Exclusion Chromatography, Lignin, Multi-angle laser light scattering, Polysaccharide, Protein, Starch, Static and dynamic light scattering.

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^* Corresponding author Agnès Rolland-Sabaté: UMR408 Sécurité et Qualité des Produits d'Origine Végétale, INRA, Université Avignon, F-84000 Avignon, France; Tel: [phone]; Fax: [phone]; E-mail: [email protected]

INTRODUCTION

Biopolymers found in nature are generally highly polydisperse. Their size and molar mass distributions are directly linked to their synthesis conditions and have an impact on their properties and their behavior in terms of degradation and other modifying processes. To understand their behavior, it is therefore important to determine these distributions. Size-exclusion chromatography (SEC, or gel permeation chromatography, GPC) is a very popular technique used for the determination of the molar mass distribution of polymers. It is a liquid chromatographic technique that allows the fractionation of molecules as a

function of their hydrodynamic volume, i.e., their size (which is proportional to their molar mass), by eluting across one or several columns filled with a porous stationary phase. The development of high-performance liquid chromatography leads to the appearance of high-performance SEC (HPSEC), which is highly precise (repeatable), robust and automatic. Since this is a size fractionation technique, the molar mass distribution is obtained by calibration of the system with standards. However, the relationship between size and molar mass is not that simple, depending on the macromolecules (in particular, in the case of branched ones), and is affected by operating conditions. That is why the development of HPSEC coupled with multi-angle laser light scattering (MALLS) detection is a real added value for the determination of molar mass distributions since light scattering gives the weight-average molar mass (

_w) at each elution volume of the chromatogram. In this chapter, a brief overview of the theory of fractionation by SEC and online light scattering detection is first given, followed by some elements on column choice and applications of HPSEC-MALLS for the characterization of some biopolymers such as polysaccharides and proteins.

SEC THEORY

Fractionation Mechanism

During elution, molecules that are too large to enter the pores of the stationary phase, are eluted in the interparticular volume of the system (or total exclusion volume, V₀), whereas molecules that are sufficiently small to freely diffuse in and out of the pores are eluted in the interparticular volume of the system (or total column volume, V_t), equal to V₀ + V_p, where V_p is the pore volume. Intermediate-size molecules enter the pores and are separated by decreasing their size; the smaller they are, the more molecules enter the pores. Elution volume is expressed as follows [1]:

(1)

(2)

V_p is the accessible volume, K_SEC is the distribution coefficient, c_p is the mean concentration of the polymer in the pore volume, and c₀ is the interstitial volume. In the case of a pure SEC mechanism, i.e., based on size only, 0 < K_SEC < 1. A K_SEC=0 corresponds to an elution in the total exclusion volume, and when K_SEC=1, the solute is eluted in the total volume. If K_SEC > 1, the separation is controlled by enthalpic interactions that depend on the chemical composition of the polymer.

SEC Calibration

The aim of calibration is to obtain a relationship that links the elution volume to the molar mass of a sample. This technique is useful when only the concentration is determined online. The column calibration must be done in the same chromatographic conditions: eluent, temperature, elution flow, injected concen-tration and volume.

The classical calibration technique is based on the analysis of a series of monodisperse standards with known molar mass and the same chemical nature as the sample to be analyzed. The calibration curve shows the plot of the logarithm of the molar mass (logM) of the standards ver...

Table of contents

• Welcome
• Table of Contents
• Title Page
• BENTHAM SCIENCE PUBLISHERS LTD.
• PREFACE
• ACKNOWLEDGEMENTS
• List of Contributors
• Editors Biography
• SECTION A. INTRODUCTION
• Molecular Weight and Molecular Weight Distribution for Biopolymers
• SECTION B. CHARACTERIZATION
• Intrinsic Viscosity Bovine Serum Albumin in Aqueous Solutions: Temperature Influence on Mark-Houwink Parameters
• Small Angle Scattering and ab initio Modeling
• High-Performance Size-Exclusion Chromatography coupled with on-line Multi-angle Laser Light Scattering (HPSEC-MALLS)
• Field-Flow Fractionation (FFF)
• Rheology of Recent Vegetal-Based Biopolymers
• Gels of Ferulated Arabinoxylans: Rheology, Structural Parameters and Microstructure
• Sol and Gel Based on Polysaccharide: Characterization and Structure-properties Relationship
• Biopolymers from Mesquite Tree (Prosopis spp.)
• Direct Measurement of Free Volume Properties in Polymeric Materials
• Structural Analysis of Sulfated Polysaccharides
• Physicochemical, Antimicrobial and Mechanical Properties of Thermoplastic Materials Based on Biopolymers with Application in the Food Industry
• Influence of Nanostructures in the Physicochemical Properties of Polysaccharide Based Biocomposites: Characterization and Applications
• SECTION C. HYDRODYNAMIC PROPERTIES
• Intrinsic Viscosity of Strong Linear Polyelectrolytes in Solutions of Low Ionic Strength and Its Interpretation
• Interrelation Between Polysaccharides and Different Surfactant Types
• SECTION D. THEORETICAL MODELS
• Theoretical Models for Biopolymers
• CONCLUSIONS