Overview
ISO 16014-3:2019 specifies a low‑temperature size‑exclusion chromatography (SEC) method for determining the average molecular weight and molecular weight distribution of polymers. The procedure uses an organic eluent at temperatures below 60 °C and calculates molecular-weight values from a calibration curve prepared with polymer standards, so it is classified as a relative method (see ISO 16014-1). The standard covers reagents, apparatus, temperature and flow control, sample and standard preparation, data acquisition, result expression and precision requirements.
Key topics and technical requirements
- Principle: SEC separation with an organic mobile phase at <60 °C; molecular-weight distribution derived from a standards-based calibration curve.
- Calibration: Use polymer molecular‑weight standards covering the analysis range; when like‑chemistry standards are unavailable, universal calibration (ISO 16014-2) is an option.
- Columns and performance: Set of columns must meet performance criteria - total theoretical plate number > 15 000, resolution factor R > 1.5 near the polymer peak and asymmetry factor ≈ 1.00 ± 0.15.
- Temperature control: Columns must be maintained within ±0.5 K; detector and injector temperature control typically within ±1 K to ensure baseline and flow stability.
- Flow and pumping: Pumping system should maintain flow rate accuracy to within ±0.3%.
- Sample and standard preparation: Dissolution, optional gentle heating/shaking, filtration to protect columns (recommended filter pore size 0.2–1 µm). The standard provides guidance on concentrations and injection practices.
- Detectors and additives: Compatible detectors and possible eluent additives (e.g., LiBr, LiCl, or sodium trifluoroacetate) are described for specific polymers to avoid aggregation or improve solubility.
- Data handling: Instructions for acquisition, processing and reporting of average molecular weight and distribution parameters; precision and interlaboratory performance are addressed.
Applications and users
ISO 16014-3:2019 is used for:
- Routine quality control and batch release testing of polymer materials
- R&D and formulation development where low‑temperature eluents are required
- Material characterization in regulatory submissions, failure analysis and supplier qualification
Typical users include polymer analytical labs, QC/QA teams, materials scientists, instrument manufacturers and standards organizations. Keywords: ISO 16014-3:2019, size‑exclusion chromatography, SEC low‑temperature method, molecular weight distribution, polymer analysis.
Related standards
- ISO 16014-1 - General principles for SEC polymer molecular‑weight determination
- ISO 16014-2 - Universal calibration method (alternative calibration approach)
- ISO 472 - Plastics vocabulary
- ISO 5725-1 / ISO 5725-2 - Accuracy, repeatability and reproducibility guidance
Use ISO 16014-3:2019 when SEC must be performed with organic eluents at controlled temperatures below 60 °C and when a standards-based, relative molecular‑weight method is appropriate.
Open preview (PDF)Plastics — Determination of average molecular weight and molecular weight distribution of polymers using size-exclusion chromatography — Part 3: Low-temperature method
