Molecular-weight distribution
Molecular-weight distribution
Material Analysis · Chromatography & Diagnostics
Gel Permeation / Size Exclusion Chromatography (GPC/SEC)
GPC/SEC analysis for polymer molecular-weight distributions, with solvent, solubility, calibration and the required Mn, Mw and dispersity results agreed.
- Price
- from£79 per sample, excl. VATA £45 service fee applies to orders under £300, excluding VAT.
- Turnaround
- 8–12 working days Preparation and scope dependent
- Available platforms
- Waters GPC 1515
- Typical outputs
- GPC/SEC chromatogramsMolecular-weight distributionAgreed Mn, Mw and dispersitySolvent, calibration and method record
Why this service
What GPC/SEC can help you understand
GPC/SEC separates dissolved molecules by hydrodynamic size. Molecular-weight results depend on the column, solvent and calibration basis; a relative calibration is not an absolute molecular-weight measurement.
Mn, Mw and dispersity
Mn, Mw and dispersity
Matched polymer comparison
Matched polymer comparison
Choose the scope
Start from the question, not the tool
The method, preparation route and reporting depth depend on what you need to decide.
Molecular-weight distribution
Molecular-weight distribution
- Best used when
- Molecular-weight distribution
- Typical result
- GPC/SEC chromatograms
- Preparation note
- Insoluble or crosslinked material cannot be represented by routine solution GPC/SEC without a separately agreed approach.
Mn, Mw and dispersity
Mn, Mw and dispersity
- Best used when
- Mn, Mw and dispersity
- Typical result
- Molecular-weight distribution
- Preparation note
- Aggregation, column interactions and filtration can bias the measured distribution.
Matched polymer comparison
Matched polymer comparison
- Best used when
- Matched polymer comparison
- Typical result
- Agreed Mn, Mw and dispersity
- Preparation note
- Absolute molar mass or specialised detector combinations require separate confirmation.
Common outputs
A result package matched to the decision you need to make
Fields, conditions, processing and file formats are confirmed before work begins.
GPC/SEC chromatograms reported with the agreed units, sample reference and measurement conditions.
Molecular-weight distribution supplied in a labelled format suitable for direct sample or condition comparison.
Agreed Mn, Mw and dispersity provided with the processing basis and quality checks agreed during technical review.
Solvent, calibration and method record included when selected in the confirmed reporting scope.
Sample requirements
What to provide before work begins
Provide representative, clearly labelled samples and identify the decision, feature or comparison that matters.
| Suitable sample | Submission requirement | Planning note |
|---|---|---|
| Soluble polymers | Identify polymer chemistry, solvent, concentration and expected molecular-weight range. | Insoluble or crosslinked material cannot be represented by routine solution GPC/SEC without a separately agreed approach. |
| Polymer solutions | Describe solubility, additives, aggregation and any insoluble fraction. | Aggregation, column interactions and filtration can bias the measured distribution. |
| Soluble polymers | Provide reference methods or standards and agree filtration, detector and calibration before analysis. | Absolute molar mass or specialised detector combinations require separate confirmation. |
Objective: state the decision, comparison or acceptance criterion the work must support.
Handling and access: declare hazards, instability, confidentiality, file constraints or special logistics before dispatch or transfer.
Questions and answers
Common planning decisions
Short answers to issues that can change preparation, scope, timing or interpretation.
Are Mn, Mw and dispersity always absolute?
No. With conventional calibration, molar-mass values are relative to the chosen standards. The report must state that basis; dispersity is Mw divided by Mn.
Can an insoluble polymer be measured?
Routine GPC/SEC requires a compatible solution. Declare insoluble fractions and crosslinking so feasibility and preparation can be assessed.
Configure the service
Send the information needed to scope GPC/SEC correctly
- Sample form, material, dimensions and quantity
- Feature or decision the result must address
- Required comparison, acceptance criterion or reference
- Preferred output and reporting depth
GPC/SEC analysisfrom£79
A £45 service fee applies to orders under £300, excluding VAT.
Typical turnaround: 8–12 working days
Configure & Book