title: Characterization of sodium carboxymethyl cellulose by comprehensive two-dimensional liquid chromatography.
abstract: Two series of sodium carboxymethyl celluloses (NaCMC) with average degrees of substitution (DS) ranging from 0.45 to 1.55 were synthesized from low molecular mass Avicel cellulose (Avicel samples) and from high molecular mass cotton linters (BWL samples). The samples were characterized by online two-dimensional liquid chromatography using gradient liquid adsorption chromatography in the first and size exclusion chromatography (SEC) in the second dimension. This method allows the simultaneous determination of the chemical composition (DS) and the molar mass distribution within the individual samples. Moreover information was obtained on the dependence of the elution volume in gradient chromatography on molar mass. As expected, evidence for a stronger influence of molar mass on gradient elution volume was found for the low molecular mass NaCMC as compared to the high molecular mass BWL samples. Finally the applicability of the method for the simultaneous separation of blends heterogeneous with respect to chemical composition (DS) and molar mass was demonstrated. Such blends cannot be efficiently separated by either SEC or gradient chromatography alone, nor by simply combining the results of both methods. Only the complete two-dimensional chromatogram can reveal the complexity of such blends, since it reveals the correlations between molar mass and chemical composition.
authors.affiliation: Fraunhofer Institute for Structural Durability and System Reliability LBF, Division Plastics, Schlossgartenstraße 6, D-64289 Darmstadt, Germany.
authors.forename: Maria
authors.initials: M
authors.lastname: Shakun
authors.affiliation: Friedrich-Schiller-Universität Jena, Humboldtstrasse 10, D-07743 Jena, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Heinze
authors.affiliation: PSS Polymer Standards Service, In der Dalheimer Wiese 5, D-55120 Mainz, Germany. Electronic address: WRadke@pss-polymer.com.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Radke
mesh_terms: D002266:Carboxymethylcellulose Sodium / Q000737:chemistry*; D002850:Chromatography, Gel; D002853:Chromatography, Liquid / Q000295:instrumentation / Q000379:methods*; D008970:Molecular Weight
chemical_list: D002266:Carboxymethylcellulose Sodium
keywords: Degree of substitution; Gradient liquid adsorption chromatography; Size exclusion chromatography; Sodium carboxymethyl cellulose; Two-dimensional chromatography