Gel Permeation Chromatography (GPC)
Gel Permeation Chromatography (GPC)
GPC is a technique which is used to determine the molecular weight of sample components. Jordi Labs operates one of the most extensive GPC facilities in the country. We currently have 42 GPC systems allowing us to provide for all your GPC testing needs. We are capable of running in nearly any solvent and can provide rapid turnaround for most analyses.
Jordi Labs produces a complete line of GPC columns providing us with unique expertise and access to a wide selection of column stationary phases. We can solve the GPC problems which others cannot.
Detection methods available for GPC analysis include:
● Ultra Violet (UV)
● Evaporative Light Scattering (ELSD)
● Refractive Index (RI)
● Right Angle Light Scattering (RALS)
● Viscometry
● Low Angle Light Scattering (LALLS)
● Fourier Transform Infrared Spectroscopy (FTIR)
Jordi Labs’ team of PhD chemists have written several white papers on GPC. Please read as much as you like.
| Title | Description | More Information |
|---|---|---|
| GPC/SEC | Discusses the factors involved in obtaining good results in size exclusion chromatography (SEC). |
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| GPC/SEC Method Development | Discusses best practices employed when designing a GPC/SEC method. |
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| GPC/SEC Method Validation | Describes Jordi Labs’ general approach to validating a chromatographic method and provides the tools you need to create a high quality validation system in your laboratory. |
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| GPC: Conventional vs. LS | Discusses the advantages and disadvantages of using conventional GPC and light scattering GPC. |
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| Molecular Weight Averages | Discusses the three different molecular weight averages that are commonly used to provide information about polymers. (mn, mw, mz) |
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We offer the following GPC test methods:
Gel Permeation Chromatography Standardized (GPC)
The sample is placed into a suitable solvent and passed through a GPC column. Sample components are separated based on molecular size and monitored by refractive index detection. Comparison with standards of known value allows the determination of the relative molecular weights of sample components.
High Temperature Gel Permeation Chromatography (GPC-H)
This method is most often applied for the analysis of polyethylene and polypropylenes. The sample is placed into trichlorobenzene in the presence of an antioxidant and passed through a GPC column at 145ºC. Sample components are separated based on molecular size. Comparison with standards of known value allows the determination of relative molecular weights for the sample components.
Gel Permeation Chromatography Tetra Detection (GPC-T)
The sample is placed into a suitable solvent and passed through a GPC column. Sample components are separated based on molecular size. Right angle light scattering, low angle light scattering, Viscometry, UV, and refractive index detection are conducted on the sample as it exits from the column enabling the determination of the absolute molecular weight and intrinsic viscosity. This technique can be used to examine polymer branching, determine polymer intrinsic viscosity, calculate polymer dn/dc, and find the percent recovery.
Gel Permeation Chromatography Fourier Transform Infrared Spectroscopy (GPC-FTIR)
The sample is placed into a suitable solvent and passed through a GPC column. Sample components are separated based on molecular size and simultaneously submitted to online solid state or liquid state FTIR analysis. Chemical identification of each sample component is attempted using comparison with reference spectrum. Changes in the chemistry of polymeric materials can be observed across the molecular weight distribution providing information otherwise unobtainable by any other method. Jordi Labs is the first analytical laboratory in the country with true online GPC-FTIR capability.
Temperature Rising Elutriation Fractionation (TREF)
TREF is a technique for the analysis of polyolefins (primarily polyethylene) which allows the separation of components with different branching structure. Thus high density and low density polyethylene can be resolved by this method. The experiment consists of placing the sample into a suitable solvent and loading it onto a GPC column. The temperature of the system is then lowered and the polyolefin precipitates onto the GPC packing as a function of its branching structure. The temperature is then raised in a controlled manner causing elution of the polymer as a function of its branching structure. Polymer branching is a crucial factor in determining material properties for polyolefins.