Reliability of the linear effective calibration method in gel permeation chromatography

1984 ◽  
Vol 49 (10) ◽  
pp. 2197-2204 ◽  
Author(s):  
Miroslav Kubín
Keyword(s):  
Separation Efficiency ◽  
Gel Permeation Chromatography ◽  
Calibration Method ◽  
Calibration Standard ◽  
Linear Calibration ◽  
Average Molar Mass ◽  
Gel Permeation ◽  
Calibration Dependence ◽  
The Given ◽  
Calculated Average

The validity of the effective linear calibration (ELC) method in gel permeation chromatography of polymers has been checked by means of computer generated chromatograms. The ratio Mw/Mn calculated using ELC form an uncorrected chromatogram is always smaller than that determined by means of the true calibration dependence, but the extent of this correction for longitudinal spreading depends on the polydispersity of both the original calibration standard and the analyzed polymer, and also on the separation efficiency of the given column. If the respective molecular weight averages of the analyzed sample and of the calibration standard differ considerably, the effective linear calibration method leads to serious systematic errors in the calculated average molar mass values.

Choice of sorbent for obtaining linear calibration dependences in gel-permeation chromatography of polymers

1980 ◽  
Vol 22 (12) ◽  
pp. 3074-3077 ◽  
Author(s):  
L.Z Vilenchik ◽  
O.I Kurenbin ◽  
T.P Zhmakina ◽  
B.G Belen'kii
Keyword(s):  
Gel Permeation Chromatography ◽  
Linear Calibration ◽  
Gel Permeation

Determination of the Mark-Houwink constants by gel permeation chromatography with correction for longitudinal spreading

1986 ◽  
Vol 51 (8) ◽  
pp. 1636-1647 ◽  
Author(s):  
Miroslav Kubín
Keyword(s):  
Gel Permeation Chromatography ◽  
Correction Factors ◽  
Gel Permeation ◽  
Calibration Dependence ◽  
Polydisperse Polymer ◽  
Universal Calibration

The determination of the Mark-Houwink constants using gel permeation chromatography data, based on a known universal calibration dependence and the recorded chromatograms of one or several characterized polydisperse polymer samples, has been modifies by including correction factors for the longitudinal spreading. Verification by means of artificial, computer generated chromatograms shows that the new procedure considerably raises the accuracy and reliability of the results obtained.

scholarly journals Molecular Characteristics and Antioxidant Activity of Spruce (Picea abies) Hemicelluloses Isolated by Catalytic Oxidative Delignification

Molecules ◽  
2022 ◽  
Vol 27 (1) ◽  
pp. 266
Author(s):  
Valentina S. Borovkova ◽  
Yuriy N. Malyar ◽  
Irina G. Sudakova ◽  
Anna I. Chudina ◽  
Andrey M. Skripnikov ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Thermogravimetric Analysis ◽  
Gel Permeation Chromatography ◽  
Molecular Characteristics ◽  
Average Molar Mass ◽  
Composition And Structure ◽  
Gel Permeation ◽  
Acetic Acid Water ◽  
Physicochemical Methods ◽  
Oxidative Delignification

Spruce (Piceaabies) wood hemicelluloses have been obtained by the noncatalytic and catalytic oxidative delignification in the acetic acid-water-hydrogen peroxide medium in a processing time of 3–4 h and temperatures of 90–100 °C. In the catalytic process, the H2SO4, MnSO4, TiO2, and (NH4)6Mo7O24 catalysts have been used. A polysaccharide yield of up to 11.7 wt% has been found. The hemicellulose composition and structure have been studied by a complex of physicochemical methods, including gas and gel permeation chromatography, Fourier-transform infrared spectroscopy, and thermogravimetric analysis. The galactose:mannose:glucose:arabinose:xylose monomeric units in a ratio of 5:3:2:1:1 have been identified in the hemicelluloses by gas chromatography. Using gel permeation chromatography, the weight average molar mass Mw of hemicelluloses has been found to attain 47,654 g/mol in noncatalytic delignification and up to 42,793 g/mol in catalytic delignification. Based on the same technique, a method for determining the α and k parameters of the Mark–Kuhn–Houwink equation for hemicelluloses has been developed; it has been established that these parameters change between 0.33–1.01 and 1.57–472.17, respectively, depending on the catalyst concentration and process temperature and time. Moreover, the FTIR spectra of the hemicellulose samples contain all the bands characteristic of heteropolysaccharides, specifically, 1069 cm−1 (C–O–C and C–O–H), 1738 cm−1 (ester C=O), 1375 cm−1 (–C–CH3), 1243 cm−1 (–C–O–), etc. It has been determined by the thermogravimetric analysis that the hemicelluloses isolated from spruce wood are resistant to heating to temperatures of up to ~100 °C and, upon further heating, start destructing at an increasing rate. The antioxidant activity of the hemicelluloses has been examined using the compounds simulating the 2,2-diphenyl-2-picrylhydrazyl free radicals.

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