Gel permeation chromatography GPC columns

The selection of the right gel-permeation chromatography (GPC) column or column combination for a special task is a multistage procedure. First, a decision about the type of column has to be made according to the polymer samples in question ... 

Although relatively unknown, the instrumentation for 2DLC was conceived and implemented by Emi and Frei (1978). They reported the valve configuration presently used in most comprehensive 2DLC systems. However, they automated neither the valve nor the data conversion process to obtain a contour map or 2D peak display. They used a gel permeation chromatography (GPC) column in the first dimension and a reversed-phase liquid chromatography (RPLC) column in the second dimension and studied complex plant extracts. 

The suspension polymerisation approach is often used in the production of polyvinyl chloride dispersions for use in plastic pipes. Polystyrene and styrenic copolymers are also produced by suspension polymerisation. The polystyrene beads are often prepared by suspension polymerisation for use as packing material in gel permeation chromatography (GPC) columns. Ion exchange resin beads are also commonly produced by suspension polymerisation. Because suspension beads are relatively large, it is easier to separate the polymer by coagulation than in the case of emulsion polymerisation. 

After evaporating the solvent, the residue was dissolved with ethyl acetate/cyclohexane (1 1), and a 2.5g portion of the solution was loaded on a gel permeation chromatography (GPC) column. As for green tea, the volume loaded to GPC was changed to a Ig portion to avoid interfering effects from the matrix. The corresponding fraction from the GPC was collected and evaporated to dryness. 

The refractive index (RI) of a mixture is a function of the composition of the mixture and the respective refractive indices of the constituents [8]. The mixture refractive index follows mixture laws such as the Lorentz-Lorenz law. Operational measuring instruments are usually differential refractometers or critical-angle re-fractometers [4]. A large disadvantage in the method is that it only provides meaningful results when a two-component system is considered. However, a differential refractometer is commonly used as a concentration detector in the effluent of a gel permeation chromatography (GPC) column for molecular weight determination. 

There were also attempts to fractionate synthetic high polymers however, it was not until 1964, when J. C. Moore of the Dow Chemical Company published his work on the preparation of Gel Permeation Chromatography (GPC) columns based on cross-linked polystyrene with controlled pore size, that a rapid increase of research activity in this field began. It was recognized almost immediately that with proper calibration, GPC was capable to provide molar mass and molar mass distribution information for synthetic polymers. Because the latter information was difficult to obtain by other methods, GPC came rapidly into extensive use. 

TSK-GEL H type columns are for gel-permeation chromatography (GPC) in organic solvents. They are packed with porous poly(styrene-divinylbenzene) resins that have a high degree of cross-linking. 

The enantioselective determination of 2,2, 3,3, 4,6 -hexachlorobiphenyl in milk was performed by Glausch et al. (21). These authors used an achiral column for an initial separation, followed by separation of the eluent fraction on a chiral column. Fat was separated from the milk by centrifugation, mixed with sodium sulfate, washed with petroleum ether and filtered. The solvent was evaporated and the sample was purified by gel permeation chromatography (GPC) and silica gel adsorption chromatography. Achiral GC was performed on DB-5 and OV-1701 columns, while the chiral GC was performed on immobilized Chirasil-Dex. 

Hie hydrolytic depolymerization of nylon-6 was followed by gel permeation chromatography (GPC), viscometry, and gravimetry. GPC determinations were performed on a Waters 150C chromatography system using benzyl alcohol as die eluant, two Plgel 10-p.m crosslinked polystyrene columns, and a differential refractometer detector. The flow rate was 1 mL/min. The concentration of the polymer solutions was 0.5 wt% and dissolution was accomplished at 130°C. 

Analyses were performed by gel permeation chromatography (GPC) and by high performance liquid chromatography (HPLC). Gel filtration of oligosaccharides was effected in a thermostated (65 <>C) column (210 X 1.5 i.d.) filled with polycrylamide gel (Bio-gel P2, 200-400 mesh Bio Rad-USA), using stilled water as eluent (flow rate 30 ml.h-1). 

In both cases, the entire method consists of four stages solvent extraction and partition, cleanup by gel permeation chromatography (GPC) and/or mini silica gel column chromatography and gas chromatography (GC) determination. Except for the central GPC, several variations occur at each stage depending on the kind of sample material and the residues to be analyzed. The variations can be combined with each other in a variety of ways according to the requirements. 

Molecular weights of the copolymers were determined by gel permeation chromatography (GPC) with four p-styragel (Haters) columns calibrated using polystyrene standards. Chloroform was used as the eluate at a flow rate 1.5 ml/min. An LKB-2140 Ultraviolet Photodiode Array detector was used to detect the polymer with a scan range from 190 to 370 nm. 

Gel permeation chromatography (GPC) was carried out on a Waters 720 GPC instrument using a methylene chloride eluant and a series of Micro-styragel columns of 10,000, 1000, 500, and 100A pore sizes. Reported values were standardized against polystyrene. 

The determination of the molecular weight of nanoparticles is performed by gel permeation chromatography (GPC). The experimental setup consists of a high performance liquid chromatography system with a size exclusion column and a refractive index detector. The nanoparticles are usually freeze-dried and dissolved in tetrahydrofuran for analysis on the system. Poly(styrene) or poly(methylmethacrylate) standards are used to calibrate the column, to enable the determination of number average molecular weight (Mn), as in... 

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