Gel permeation chromatography of low molecular weight materials with high efficiency columns

1977 ◽  
Vol 49 (7) ◽  
pp. 898-902 ◽  
Author(s):  
Anoop. Krishen ◽  
Ralph G. Tucker
Keyword(s):  
Molecular Weight ◽  
High Efficiency ◽  
Gel Permeation Chromatography ◽  
Low Molecular Weight ◽  
Gel Permeation

scholarly journals Fractionation of lignosulphonates released during the early stages of delignification

1983 ◽  
Vol 61 (2) ◽  
pp. 416-420 ◽  
Author(s):  
Norman G. Lewis ◽  
David A. I. Goring ◽  
Alfred Wong
Keyword(s):  
Molecular Weight ◽  
High Performance ◽  
Black Spruce ◽  
Gel Permeation Chromatography ◽  
Bimodal Distribution ◽  
High Yield ◽  
Low Molecular Weight ◽  
Lower Yield ◽  
Spruce Wood ◽  
Gel Permeation

High-yield spent bisulphite liquor (HY-SBL) from sulphonated black spruce wood (Piceamariana) was fractionated by gel permeation chromatography (GPC) and by high-performance liquid chromatography (HPLC). The GPC fractionation gave a wide bimodal distribution, whereas with HPLC, a more detailed resolution was seen with the bulk of the fraction giving several clearly defined peaks. The paucidisperse material was further concentrated by a bulk fractionation of the crude SBL which included complexing the lignosulphonates with dicyclohexylamine. The isolated paucidisperse material was found to be dialyzable and to constitute 90% of the lignosulphonate in the sample of SBL. If the bisulphite pulp obtained was recooked in fresh acid sulphite liquor to a lower yield, most of the lignosulphonate dissolved was widely polydisperse with no indication of the discrete components resolvable by HPLC. However, 25% of the lignin made soluble was in the form of the paucidisperse fractions. In all, we were able to obtain about 50% of the lignin in spruce wood as a relatively low molecular weight lignosulphonate resolvable into discrete fractions by HPLC.

Comparison of Number—Average Molecular Weights Calculated by GPC and Membrane Osmometry

1973 ◽  
Vol 46 (1) ◽  
pp. 115-126
Author(s):  
M. R. Ambler ◽  
R. D. Mate
Keyword(s):  
Molecular Weight ◽  
Gel Permeation Chromatography ◽  
Appreciable Amount ◽  
Diffusion Limit ◽  
Low Molecular Weight ◽  
Molecular Weights ◽  
True Value ◽  
Usual Manner ◽  
Gel Permeation ◽  
Polymer Species

Abstract Data are presented which show that when a polymer contains an appreciable amount of low molecular weight species below the diffusion limit of the osmometer membrane, the osmotic molecular weight, Mn, is generally higher than the Mn calculated from gel-permeation chromatography (GPC). Experiments were performed on samples of poly(vinylchloride) (PVC) and high-cis poly (butadiene) polymers. Osmotic data were obtained in the usual manner, while GPC data were obtained using the universal calibration approach. It was found that when all polymer species below approximately 10,000 molecular weight were excluded from the calculation of Mn by GPC, agreement in Mn was obtained between membrane osmometry and GPC. The data obtained suggest that the choice of Mn as measured by membrane osmometry in the calibration of the GPC should not be done casually, as the measured Mn may not reflect the “true” value of that sample, especially when the polymer sample contains an appreciable amount of low molecular weight material.

Molecular Weight Measurements of Low Molecular Weight Heparins by Gel Permeation Chromatography

1997 ◽  
Vol 77 (04) ◽  
pp. 668-674 ◽  
Author(s):  
B Mulloy ◽  
C Gee ◽  
S F Wheeler ◽  
R Wait ◽  
E Gray ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Low Molecular Weight Heparin ◽  
High Performance ◽  
Gel Permeation Chromatography ◽  
Low Molecular Weight ◽  
Low Molecular Weight Heparins ◽  
Molecular Weights ◽  
Calibration Table ◽  
Gel Permeation ◽  
Degraded Material

SummaryThe molecular weight profiles of low molecular weight heparin samples have been measured by high-performance gel permeation chromatography using as calibrant the heparinase-degraded material (90/686) now established as the 1st International Reference Preparation (IRP) Low Molecular Weight Heparin for Molecular Weight Calibration. Use of the calibrant as a broad molecular weight standard is described and a calibration table provided based on data collected over several years in one laboratory.In order to confirm the assignment of degree of polymerisation to resolved oligosaccharide peaks in the calibrant, molecular weights of oligosaccharides fractionated from the 1st IRP were independently determined by fast atom bombardment mass spectrometry (FAB MS).The molecular weight distributions of commercial low molecular weight heparins have been characterized. Measurements of molecular weight parameters of heparin molecular weight standards from several sources provide comparisons between the molecular weight scales of this and other studies.

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