ISO 16560:2015

Overview

ISO 16560:2015 specifies a standardized HPLC method for the determination of polyethylene glycol (PEG) content in aromatic and aliphatic non‑ionic ethoxylated surfactants (R‑(O‑C2H4)n‑OH). The method uses reversed‑phase liquid chromatography with an Evaporative Light Scattering Detector (ELSD) or Charged Aerosol Detector (CAD) and external calibration (PEG molar mass = 1 000 g·mol‑1). It is applicable to ethoxylated products soluble in methanol or methanol/water and for PEG mass fractions ≥ 0.1%. PEGs with molar mass < 400 g·mol‑1 and small glycols/glycerol (monomeric ethylene glycol, di‑, tri‑ethylene glycol, glycerol) are not detected.

Key topics and technical requirements

• Scope & limits: PEG ≥ 0.1% (m/m); PEG molar mass ≥ 400 g·mol‑1; sample solubility in methanol or methanol/water.
• Separation principle: reversed‑phase HPLC where PEG elutes early and ethoxylated surfactants are retained.
• Detectors: ELSD or CAD are specified to avoid interference from volatile solvents.
• Calibration: external calibration with PEG 1 000 (typical calibration solutions 0.01, 0.05, 0.10, 0.25 g·L‑1) and a log–log calibration curve of peak area vs. PEG mass.
• Chromatographic conditions (as given): C18 column (5 µm, 250 × 4.6 mm), flow 1.0 mL·min‑1, injection 20 µL, gradient from methanol/water to 100% methanol (to elute ethoxylates), room temperature.
• Sample prep: dissolve weighed sample in mobile phase (e.g., 80/20 methanol/water), dilute appropriately per expected PEG content, filter (0.45 µm) if needed.
• Precision: repeatability limit ≤ 0.2% (95% probability); reproducibility limit ≤ 0.8% (95% probability).
• Reporting: include sample identification, reference to ISO 16560, analytical conditions (temperature, ELSD/CAD settings), deviations and incidents.

Applications

ISO 16560:2015 is intended for laboratories performing quantitative analysis of PEG contamination or formulation content in nonionic ethoxylated surfactants. Typical uses:

• Quality control in surfactant and detergent manufacturing
• Raw material verification and supplier testing
• Formulation development and R&D for personal care, industrial cleaners, agrochemical surfactants
• Regulatory or specification compliance testing
• Contract and third‑party analytical laboratories providing HPLC PEG determination

Who should use this standard

• Analytical and QC chemists in surfactant, detergent, cosmetics and chemical manufacturing
• Test laboratories and contract research organizations (CROs)
• Regulatory and compliance teams verifying product composition
• Method developers needing a validated HPLC procedure for PEG content

Related standards

• ISO 3696 - Water for analytical laboratory use
• ISO 607 - Sample division for surfactants and detergents
• ISO 5725‑2 - Precision (repeatability and reproducibility) of measurement methods
• EN 12582 - European standard on which ISO 16560 was developed

Keywords: ISO 16560:2015, polyethylene glycol, PEG content, nonionic ethoxylated surfactants, HPLC method, ELSD, CAD, reversed phase HPLC, surfactant quality control.