A Universal Calibration for Gel Permeation Chromatography

Abstract

Gel permeation chromatography is one of the most powerful techniques for characterizing the polydispersity of polymeric materials. A versatile commercial apparatus has been used successfully in numerous laboratories on various problems of molecular weight distributions. But one of the difficulties still unsolved is the problem of calibration, i.e., the relation between elution volume and molecular weight. Some authors have assumed that retention time depends on the contour length of the molecular chain. Others think that it is more reasonable to use the radius of gyration or some average volume of the polymer molecule as the calibration parameter. In a recent paper we have reported GPC retention times of a series of polystyrenes exhibiting different molecular structures: linear, star-shaped, and comb-like. All were of known molecular weight and of low polydispersity. Obviously the conventional calibration method, where the logarithm of molecular weight is plotted against elution volume, does not yield a universal curve for all the samples. Retention times for branched samples were always larger than those for the linear homologs of the same molecular weight. We therefore tried using the hydrodynamic volume as the calibration parameter.

Analysis using size exclusion chromatography of poly( N -isopropyl acrylamide) using methanol as an eluent

“…The peak retention time of these polymers was then used to calibrate the system to afford both a SEC calibration plot (see Supporting information) and a Universal calibration (Fig. 3) by plotting log(M[η]) versus retention time [34].

Fig. 3Calibration of Agilent PolarGel columns with linear PNIPAM polymers.

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Size‐Exclusion Chromatography in Single and Mixed Eluents: Effects of Sorption of Solvent and Polymer Solutes on Novel TSK‐Gel Super AW Columns

“…[1] Later experiments with PS-DVB confirmed, also, the validity of the u.c. The earlier equation was thoroughly tested with crosslinked polystyrene-divynilbenzene (PS-DVB) gels for homopolymers and copolymers with linear and branched structures.…”

“…[5,28,29] Among them, it deserves to be remarked that the pioneer proposition of Benoit et al [1,30] the u.c. [5,28,29] Among them, it deserves to be remarked that the pioneer proposition of Benoit et al [1,30] the u.c.…”

“…concept, as suggested by Grubisic et al [1] holds, and the elution volume, V e , is related to the solute hydrodynamic volume, V h , through the known equation: In an "ideal" situation, only entropic effects take part and the separation of macromolecules is accomplished by size.…”

Molecular Mass Characterization of Glycosaminoglycans with Different Degrees of Sulfation in Bioengineered Heparin Process by Size Exclusion Chromatography

“…A more accurate calibration curve may use the plot of log([η]M) versus retention time, where [η] denotes the intrinsic viscosity and M is the weight average relative molecular mass. The term [η]M is proportional to the solute’s hydrodynamic volume, and Benoit et al [17] demonstrated that a number of polymers with different configurations (e.g., linear, comb-branched, star-branched) all conformed to a single plot of log([η]M) versus the elution volume. However, intrinsic viscosity measurement usually requires large quantities of sample, which is very costly for heparin and heparosan oligosaccharides.…”