Fractionation by size exclusion chromatography

The partially hydrolysed material was fractionated by size exclusion chromatography on a Bio Gel PIO (Bio Rad) column (2,6 x 90 cm) and eluted with 50 mM ammonium hydrogen carbonate at 20 ml/h and fractions of 3.2 ml each were collected. Fractions 45-70 were pooled and subjected to HPAEC-PAD for further separation. 

Trubetskoj, O. A., Trubetskaya, O. E., Afanaseva, G. V., Reznikova, O. I., and Saiz-Jimenez, C. (1997). Polyacrylamide gel electrophoresis of soil humic acid fractionated by size-exclusion chromatography and ultrafiltration. J. Chromatogr. A 767, 285-292. 

Many of the problems of MALDI of polydisperse polymers can be overcome by using a combination of an initial fractionation by size exclusion chromatography (sec) followed by MALDI, taking advantage of the enormous sensitivity of MALDI to analyze the minute amoimts of polymer eluted from the sec. This is probably now the best available method for getting MWD information but is complex. 

We have previously reported the design of mixed hydrophilic/hydrophobic hydrogels containing PHEMA and polysaccharide segments, in which the polysaccharide structure is a hydrosoluble hemicellulose with a comparatively low molecular weight obtained from spruce chips by a steam explosion technique and fractionated by size exclusion chromatography (SEC) (1), In this paper we summarize earlier work and add some new results concerning controllability. 

Kukrer B, Fihpe V, van Duijn E, Kasper PT, Vreeken RJ, Heck AJR, Jiskoot W. Mass spectrometric analysis of intact human monoclonal antibody aggregates fractionated by size-exclusion chromatography. Pharm Res 2010 27 2197-204. 

Montaudo and co-workers [8] reported on a SEC/MALDI study of molar mass distribution in two random copolyesters polybutylene adipate - polybutylene sebacate (PBA - PBSe) and polybutylene sebacate - polybutylene sccinate (PBSe - PBSu). MALDI allows desorption and when polydisperse polymer samples are fractionated by size exclusion chromatography, they yield fractions with very narrow distributions which, when analysed by MALDI give mass spectra with molar mass values in excellent agreement with those obtained by conventional techniques. These workers derived the following equation for the molar mass of the copolymer molecule ... 

Fractal dimension Neutrons scattering If the magnitude of the scattering wave vector q is such that q < R(m) for all m, the scattered intensity per monomer is only q dependent and the fractal dimension D can be measured. This experimental condition was obtained with a sample, at a given , fractionated by size exclusion chromatography in order to select only clusters having a size larger than 20 nm. The result is ... 

Yanagida, A., Kanda, T., Shoji, T., Ohnishi-Kameyama, M., and Nagata, T., Fractionation of apple procyanidins by size-exclusion chromatography, /. Chromatogr. A, 855, 181, 1999. 

Three gradients of 0.0-0.5 M sodium chloride were run consecutively at 4°C in 0.05 M sodium acetate-acetic acid, 1 mM sodium azide, pH 5.25, followed by 0.05 M sodium acetate-acetic acid, 1 mM sodium azide, pH 3.5, and finally by 0.05 M sodium dihydrogen phosphate-disodium hydrogen phosphate (approx. 1 3), 1 mM sodium azide, pH 7.0. After sample application, the column was washed with the starting buffer to remove any non-bound compounds. Elution was continued with the high salt buffer. Fractions of 4 ml were collected and assayed for reactivity towards ninhydrin and for electric conductivity (salt concentration) after 75-fold dilution of a 100-pl aliquot. Ninhydrin-positive fractions were pooled for each peak, concentrated, and desalted by size exclusion chromatography (see above). 

The parity of the pooled fractions from the rnn was assessed by size exclusion chromatography to be 92.7% after pooling selected fractions. The anthors did not comment however on the yield of the process or its snitability for farther scaleup into manufacturing. 

Dextrans are bacterial and yeast polysaccharides made up of (a 1—>6)-linked poly-D-glucose all have (al—>3) branches, and some also have (al—>2) or (al—>4) branches. Dental plaque, formed by bacteria growing on the surface of teeth, is rich in dextrans. Synthetic dextrans are used in several commercial products (for example, Sephadex) that serve in the fractionation of proteins by size-exclusion chromatography (see Fig. 3-18b). The dextrans in these products are chemically cross-linked to form insoluble materials of various porosities, admitting macromolecules of various sizes. 

Using the normal addition procedure (02 diffusion into a 75/25 benzene/THF solution of poly(styryl)lithium) the 37% dimer fraction analyzed for 19% alkyl radical dimer and 18% macroperoxide after LiAlH4 reduction. The yield of macroperoxide was also confirmed by thermal decomposition experiments in refluxing toluene, followed again by size exclusion chromatography analysis of the dimer fraction. The amount of hydroperoxide could be deduced from the difference between the amounts of total peroxide (determined by iodometric titration) versus the amount of macroperoxide determined by LiAlH4 reduction. 

Gardner, W.S., Landrum, P.F. and Yates, D.A., 1982. Fractionation of metal forms in natural waters by size exclusion chromatography with inductively coupled argon plasma detection. Anal. Chem., 54 1196-1198. 

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