Overview - ISO 19619:2018 (Surface active agents, propylene oxide)
ISO 19619:2018 specifies an analytical procedure for determining free propylene oxide in surfactants produced from propylene oxide copolymers. The method uses headspace gas chromatography (HS‑GC) with GC‑FID for quantitative analysis (external calibration) and GC‑MS for confirmatory qualitative identification. It is applicable to propylene oxide adducts, polyethers and polyglycol esters.
Key topics and technical requirements
- Principle: equilibrate sealed headspace vials and analyze the vapor phase by temperature‑programmed GC. Quantification by GC‑FID (external calibration); confirmation by GC‑MS (ion abundance ratios).
- Sample preparation: typical procedure - weigh ~1.0 g sample into headspace vials, add 5 mL N,N‑dimethylacetamide (DMAC), vortex, equilibrate and analyze (three replicate vials recommended).
- Calibration: prepare propylene oxide working solutions by difference weighing or commercial certified vials; generate multi‑point calibration (0 to 100 µg/mL example). For standard addition, calibration must be linear with correlation coefficient ≥ 0.995 and intercept SD ≤ 10% of mean.
- Identification criteria: match retention time with standard and confirm by MS relative ion abundances (propyl oxide detect ions m/z 28, 58, 27, 31 with established relative ratios and allowed deviations as specified).
- Reagents & apparatus: analytical‑grade reagents, DMAC (or validated solvent alternatives such as DMF/DMSO), high‑purity carrier gases (N2 for GC‑FID, He for GC‑MS), analytical balance, HS autosampler, capillary GC column (example: 30 m × 0.32 mm, 6% cyanopropylphenyl/94% dimethylpolysiloxane), FID and MSD.
- Quality and statistical requirements: precision, repeatability and reproducibility are addressed (statistical data and ring trial results included in annexes).
- Safety: the standard warns about hazardous materials and requires users to observe appropriate safety and environmental controls.
Applications - who uses ISO 19619:2018
- Surfactant and specialty chemical manufacturers - routine quality control of propylene‑oxide‑based adducts.
- Analytical and contract testing laboratories - validated HS‑GC methods for determining residual monomer.
- R&D teams - method development and confirmation testing for polyether and polyglycol ester products.
- Regulatory and compliance groups - documentation of free propylene oxide content for safety and product specifications.
Keywords: ISO 19619:2018, propylene oxide, headspace GC, HS‑GC, GC‑FID, GC‑MS, surfactants, propylene oxide adducts, polyethers, analytical procedure, calibration.
Related standards
- ISO 607 - Surface active agents and detergents - Methods of sample division
- ISO 3696 - Water for analytical laboratory use - Specification and test methods
This summary highlights practical use, instrumentation, calibration and qualification requirements from ISO 19619:2018 for laboratories implementing residual propylene oxide testing in surfactant products.