Overview
ISO 13741-2:1998 defines a headspace capillary-column gas chromatography (GC) method for quantifying residual monomers and other organic components in aqueous polymer dispersions and rubber latices (natural and synthetic). Part 2 (headspace method) complements Part 1 (direct liquid injection) and provides a sensitive, chromatographic alternative to older distillation/titration methods for trace-level volatile analysis required by health and environmental regulations.
Key topics and technical requirements
- Scope: Determination of residual monomers and saturated/unsaturated volatile organics in aqueous dispersions and latices using headspace GC.
- Principle: Sample aliquot is diluted with water and a water‑miscible solvent containing an internal standard and inhibitor; sealed in a headspace vial; thermally equilibrated; headspace vapors sampled and analyzed by capillary-column GC with a flame ionization detector (FID).
- Typical analytes: acrylic/methacrylic esters, butadiene, styrene, vinyl acetate, ethylbenzene and other volatile by‑products.
- Reagents & solvents: high‑purity water (ISO 3696), carrier gas (He or N2), internal standard (e.g., dioxane), dimethylacetamide (DMAc) or dimethylformamide (DMF), polymerization inhibitor (e.g., BHT).
- Apparatus & column: automated headspace sampler, GC with FID and temperature programming, capillary column typically 30 m × 0.25 mm with 1 µm dimethylpolysiloxane film (typical operating conditions are provided in the standard).
- Calibration & quantitation: calibrate by determining response factors relative to the internal standard; calculate mass fraction (mg/kg). Typical response factor examples: ethylbenzene ≈ 0.1, styrene ≈ 0.2.
- Sample prep & conditions: ~0.5 g sample + 1 mL water + 2 mL internal standard solution; homogenize (30 min–4 h or roll 24 h); equilibrate at 90 °C for 1 h prior to analysis.
- Limits & precision: detection limit reported as 10 mg/kg (results below reported as
Open preview (PDF)Plastics/rubber — Polymer dispersions and rubber latices (natural and synthetic) — Determination of residual monomers and other organic components by capillary-column gas chromatography — Part 2: Headspace method
