Gel permeation column

Packing gel permeation column. Suspend 50 g of Bio-Beads in the GPC eluting mixture and allow the beads to swell overnight. Pour the suspension all at once into the chromatographic column (capacity ca 180 mL). Once the gel has settled to a height of... 

Elute the gel permeation column with the GPC eluting mixture at S.OmLmin To do so, set the determined parameters beforehand, e.g. ... 

Fish tissue is homogenized with a Polytron apparatus using methanol as a solvent, or extracted in a ball mill with hexane. The extracts are evaporated to dryness, dissolved in ethyl acetate toluene, and cleaned up on a gel permeation column followed by an alumina column. Analysis is performed by GC/NPD (Muir et al. 1981). Recovery is acceptable (79-97%) and limit of detection is 10 ng/g (Muir et al. 1981). 

Acetate buffer extn, online cleanup on Progel-TSK gel-permeation column, trace enrichment on PLRP-S, 15-25... 

T he partitioning of a solute between the stationary and mobile phases of a gel permeation column is a function of the molecular size and shape of the solute and the size distribution of gel pores separating the two phases. For a gel permeation column operating under conditions in which an equilibrium distribution of solute between the phases is ob-... 

HPLC system fitted with a Zorbex Bio series GF250 column (Du Pont Company, Wilmington, DE) or equivalent gel-permeation column capable of fractionation up to 250,000 Mr... 

Low concentrations of thiol groups can be detected by reaction with CHa203 HgN03. The removal of excess of reagent from the labeled thiol is achieved simultaneously with the analysis. This analysis is carried out by gel-permeation column chromatography with continuous monitoring of the 0 radiation. This technique has been applied to the analysis of proteins which contain thiol groups [205]. 

Iron-containing compounds in biological and clinical samples have been studied by separating them on chromatographic columns that were coupled to inductively coupled plasma mass spectrometers. Four iron-containing proteins, namely ferritin, haemoglobin, myoglobin and cytochrome-c were separated on a gel permeation column (Takatera and Watanabe, 1991). The absolute detection limits were 0.01-1 mg for the four proteins when 10 ml injections of samples were analysed. In other research, excess iron accumulations in human and animal... 

A gel permeation column used in conjunction with an Auto- ... 

Methyl-4-trimethylsiloxybutyl Phenyl Tellurium1 Into an argon-flushed, 50-ml flask fitted with a magnetic stirrer are placed 86 mg (1 mmol) of 2-methyltetrahydrofuran and 3 ml of dichloromethane. 3 mg (0.01 mmol) of zinc iodide and 375 mg (0.3 ml 1.35 mmol) of phenyl trimethylsilyl tellurium are added to the stirred solution at 20°. The mixture is stirred at 20° for 6 h, pyridine is then added, and the mixture is concentrated under vacuum at 20°. The residue is chromatographed on a short column of silica gel with chloroform as eluent. The chloroform is evaporated and the residue is rcchromatographed on a preparative gel-permeation column with chloroform as eluent yield 260 mg (71%) light-yellow oil. 

Figure 5-5. Gel permeation column with an attached upper buffer reservoir. (Courtesy of I. M. Easterday, Pharmacia Fine Chemicals, Inc.)...

Gel permeation columns may be left unattended during stabilization or chromatographic separations. However, if this is done the column should be provided with a safety loop to prevent it from running dry. Two ways of constructing a safety loop are illustrated in Figure 5-9. This device functions as a siphon. When the level of solution from the reservoir reaches the level of the column outlet (dashed line), the siphon is broken and the column flow ceases. 

Microcystins were first purified by Botes et al in 1982, and, since then, many different approaches " have been adopted for the isolation of microcystins from cyanobacterial cells. The most widely used proce-dures are as follows The lyophilized cyanobacterial cells which contain microcystins are extracted with organic solvents several times, and then the extracts are applied to multistep column chromatography and thin-layer chromatography.For example, Harada et al. established an effective analysis method for microcystins RR and LR. They used 5% aqueous acetic acid solution as an extracting solvent and isolated microcystins by using preparative or semipreparative liquid chromatography with ODS, silica gel, or gel permeation columns. 

Corredig, M., Kerr, W. and Wicker, L. 2000. Molecular characterisation of commercial pectins by separation with linear mix gel permeation columns in-line with multi-angle light scattering detection, Food Hydrocolloids, 14 4-47. 

C76 fullerene [135113-15-4] M 912.85, melts above 350". It is now available commercially. After the sequential removal of and C70 fullerenes from soot extracts (see above) on gel permeation columns (e.g. Buckyclutcher 1 column), C76 and higher fullerenes are obtained. These are further separated on a Tridait-TriDNP functionalised silica column. After two HPLC runs on a Cjg reverse phase (Vydac 201 TP C,g) column and eluting with 1 1 MeCN/toluene, pure C76 fuUerene is obtained. The identity is confirmed by HPLC/GPC system with Waters 600E UV/VIS detection, mass and NMR spectroscopy. [Seleque et al. In Kadish and Ruoff (Eds) Fullerenes Recent Advances in the Chemistry and Physics of Fullerenes and Related Mfltena/i The Electrochemical Soc. Inc, Pennington, NJ, 1994 ISBN 1566770823, Diederich Whetten Acc Chem Res 25 119 1992, Diederich et al. Science 254 1768 1991.]... 

Though the absolute methods for the determination of molecular weights are well established, both theoretically and experimentally, the absolute measurements are difficult to carry out, are time-consuming, and often require expensive apparatus. For these reasons, for routine determinations of moleculcu- weight, the much faster secondary methods, such as solution viscosity and gel permeation chromatography, are commonly used. These methods require prior establishment of empirical relationships that relate the molecular weight to the viscosity of the polymer solution or to the retention times in a gel-permeation column. Once such calibration has been done, the secondary methods provide a fast, simple, and accurate... 

The HPLC analysis of a mixture of phenylchlorosilanes using gel permeation columns is described. The method is applicable to a variety of organometallics or other compounds that are sensitive to air and water. 

Gel permeation columns were selected for this task because (1) the highly polar nature of the analytes precludes adsorption chromatography (the chlorosilanes and their tin analogues are too strongly adsorbed) and (2) because the required removal of water from solvents would have much less effect on retention times. 

The efficiency of a gel permeation column is markedly influenced by the mobile phase flow rate and working at high flow rates is disadvantageous. 

Size exclusion chromatography is used to separate compounds that differ in size from each other, e.g. a series of polymers. It is based on the principle of molecular sieving . Special columns called gel filtration or gel permeation columns are employed. These columns contain particles with a defined pore size that allow only small molecules to penetrate them, thus the largest molecules in the mixture reach the detector hrst, followed by small molecules followed by solvent. It is often used for desalting applications as well as for determining the molecular weight of compounds. 

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