SEC/GPC Software for Molecular-Weight Distribution and Polymer Characterization
Updated: Jul 23
Chromperfect SEC/GPC software provides specialized tools for size exclusion chromatography and gel permeation chromatography, including SEC calibration, molecular-weight-distribution analysis, polymer characterization, advanced plotting and flexible reporting.
The software can be used with chromatographic data acquired directly through a compatible Chromperfect system or with supported third-party data imported through Chromperfect Unite. This allows laboratories to add dedicated SEC/GPC analysis capabilities without necessarily replacing their existing chromatography acquisition platform.
SEC/GPC Theory Video Series
Chromperfect has developed a three-part SEC/GPC Theory Series covering the scientific principles behind size exclusion chromatography and gel permeation chromatography. Although Chromperfect software is referenced throughout the series, the underlying theory applies broadly to SEC/GPC analysis and other chromatography data systems.
Part 1 — SEC Integration Theory
Learn how an SEC chromatogram is converted into molecular-weight information, including baseline selection, noise treatment, internal-standard correction, detector response, molecular-weight averages, and fractions.
Part 2 — SEC Calibration Theory
Explore molecular-weight averages, SEC calibration curves, universal calibration, viscosity relationships, and the use of narrow and broad molecular-weight standards.
Part 3 — Advanced SEC Theory
Learn how to interpret molecular-weight-distribution plots and understand axial correction, calculated molecular-weight calibration plots, polymer fractionation, and advanced distribution analysis.
What Are GPC and SEC?
Gel permeation chromatography and size exclusion chromatography provide essential information about polymer molecular weight and molecular weight distribution. Chromperfect GPC software provides specialized tools for processing, calibrating, reviewing, and reporting GPC and SEC chromatographic data.
Gel permeation chromatography, commonly abbreviated as GPC, and size exclusion chromatography, or SEC, separate molecules according to their effective molecular size in solution.
The term GPC is frequently used for the analysis of polymers in organic solvents, while SEC is often used more broadly. Although the terminology may vary between laboratories and industries, both techniques are commonly used to determine the molecular weight distribution of polymers and other macromolecules.
Unlike conventional chromatography, where individual compounds are normally identified and quantified as separate peaks, a GPC or SEC chromatogram often contains a broad distribution representing polymer molecules of many different sizes.
Dedicated GPC software is therefore required to convert the chromatographic response and column calibration into useful molecular weight information.
Chromperfect GPC Software for Polymer Analysis
The Chromperfect SEC/GPC application module extends Chromperfect beyond conventional chromatographic integration and calibration.
It allows laboratories to process GPC and SEC chromatograms, establish the relationship between elution time and molecular weight, calculate molecular weight distributions, and create specialized plots and reports.
Chromperfect supports three principal SEC plot types:
SEC chromatogram plots
Molecular weight distribution plots
SEC calibration plots
Molecular weight distribution plots can display differential and cumulative distributions using a logarithmic molecular weight scale. These plots help users visualize how the polymer sample is distributed across different molecular weight ranges.
The software can also calculate and report commonly used molecular weight averages and distribution information, including number-average molecular weight, weight-average molecular weight, and polydispersity.
Narrow-Standard and Universal Calibration
A conventional narrow-standard SEC calibration uses a series of standards with relatively narrow molecular weight distributions.
The known molecular weight of each standard is associated with its measured elution time. The resulting calibration curve establishes the relationship between chromatographic retention and molecular weight across the working range of the column.
Chromperfect also supports universal calibration approaches for situations in which the calibration standards and samples are chemically different.
This is important because SEC separation is based on molecular size in solution rather than molecular weight alone. Two polymers with the same molecular weight may have different hydrodynamic volumes and may therefore elute at different times.
Where appropriate information is available, Chromperfect can use Mark–Houwink constants to account for the relationship between molecular weight, intrinsic viscosity, and hydrodynamic volume. Measured intrinsic viscosity values may also be used when suitable Mark–Houwink constants are unavailable or considered unreliable.
Broad-Standard Calibration Options
Narrow molecular weight standards are not available for every polymer. In these situations, a characterized broad molecular weight distribution standard may be used.
Chromperfect supports several broad-standard calibration approaches.
The Integral method uses a molecular weight distribution table for the broad standard. This table relates cumulative distribution values to known molecular weights.
The Hamielec method can use known Mn and Mw values for a broad standard to iteratively establish a calibration curve that corresponds to the measured chromatographic profile.
The Yau method builds on the broad-standard approach by accounting for the effect of column broadening. This can help compensate for distortion caused by diffusion as the sample passes through the SEC column.
The appropriate calibration method depends on the standards, reference data, detector response, polymer chemistry, column performance, and analytical objective of the laboratory.
Molecular Weight Distribution and Axial Correction
Real SEC columns do not produce perfect separation. Diffusion and other column effects broaden the observed chromatographic profile, even when the injected material has a very narrow molecular weight distribution.
This broadening can influence the calculated molecular weight distribution.
Chromperfect includes axial correction capabilities intended to account for the contribution that column broadening makes to the measured distribution. The software can use a column sigma value when calculating corrected molecular weight information.
Because axial correction and advanced calibration require suitable method development and reliable reference information, their use should be determined by an experienced SEC chromatographer.
Analyze Chromperfect and Third-Party Data
The Chromperfect SEC/GPC module can be applied to chromatographic data acquired directly within a compatible Chromperfect system.
It can also form part of a workflow in which another chromatography data system continues to control the instrument and acquire the original data.
Chromperfect Unite enables supported third-party chromatography files to be converted and processed within Chromperfect. For chromatography data systems that support AIA/NetCDF export, the typical workflow is:
Existing CDS acquisition → AIA/NetCDF .CDF export → Chromperfect Unite import → Chromperfect SEC/GPC analysis
This can allow a laboratory to retain its existing acquisition platform while using Chromperfect for specialized GPC or SEC processing and reporting.
The source chromatography data system must be able to export a suitable AIA/NetCDF .CDF file. The transfer is also one-way. After import, Chromperfect processes the chromatography within its own file structure. Integration changes, molecular weight calculations, calibration changes, and reports created in Chromperfect are not transferred back into the original CDS.
Instrument control compatibility and data analysis capability should therefore be considered separately. The ability to analyze an exported file does not mean that Chromperfect can directly control the instrument that originally produced it.
Flexible Reporting for GPC and SEC Results
Chromperfect reporting tools can be used to create reports containing chromatograms, molecular weight distributions, calibration information, calculated molecular weight averages, and other application-specific results.
Processed data can also be preserved in Chromperfect Bound files. A Bound file contains the processed chromatogram together with the method, calibration information, integration results, and associated reporting information used to produce the result.
This creates a complete processed record that can be reopened and reviewed without depending on external copies of the original method and calibration files.
How the SEC/GPC Module Is Licensed
Chromperfect SEC/GPC software is a separately licensed application module. It is not automatically included with a standard Chromperfect main, analysis, or Unite license.
Once the SEC/GPC application module has been purchased for a Chromperfect system, it can be used with any Chromperfect main or analysis license within that licensed system.
The type of base Chromperfect license required depends on the intended workflow.
A Chromperfect main license may provide data acquisition and analysis for a compatible instrument. An analysis license can be used where acquisition is not required. A Chromperfect Unite license supports the analysis of Chromperfect data and supported third-party data files.
The SEC/GPC module adds the specialized polymer calibration, molecular weight distribution, plotting, and reporting functionality to the appropriate Chromperfect analysis environment.
Is Chromperfect Suitable for Your GPC Workflow?
A suitable GPC or SEC software configuration depends on several factors:
The instrument and detector being used
Whether Chromperfect or another CDS will acquire the data
Whether the existing CDS can export AIA/NetCDF .CDF files
The required calibration approach
The available narrow or broad molecular weight standards
The polymer, solvent, temperature, and detector response
The required molecular weight calculations, plots, and reports
Chromperfect can support both fully integrated workflows and independent data analysis workflows, but the exact configuration should be confirmed before purchase.
Contact the Chromperfect team with details of your instrument, detector, existing data system, available export formats, calibration standards, and reporting requirements so that the appropriate acquisition, Unite, and SEC/GPC licensing can be identified.
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