ISO 24047:2021

Overview

ISO 24047:2021 - "Plastics - Polyethylene (PE) and polypropylene (PP) thermoplastics - Determination of metal content by ICP-OES" specifies a laboratory method to determine metal content in PE and PP using inductively coupled plasma optical emission spectrometry (ICP‑OES). The standard covers sample preparation (ashing/digestion), reagent and apparatus requirements, instrument set‑up, calibration, calculation of results and reporting. It applies to base polymers, PE/PP copolymers and blends and addresses common metals such as magnesium (Mg), aluminium (Al), calcium (Ca), zinc (Zn), chromium (Cr), titanium (Ti), iron (Fe), antimony (Sb), copper (Cu), lead (Pb) and cadmium (Cd). Mercury (Hg) is excluded due to volatility.

Key topics and technical requirements

• Principle: Samples are incinerated/digested, dissolved, nebulized and analyzed by ICP‑OES; emission intensity is proportional to element concentration.
• Sample preparation: Cleaning glassware, sample ashing (muffle furnace at ~750 °C), acid dissolution (nitric acid), filtration/centrifugation and volumetric dilution.
• Reagents and standards: Use analytical grade reagents and multi‑ or single‑element standards; working standards typically at 0.50, 1.00, 5.00, 10.00 and 20.00 mg/L in 3–5% HNO3.
• ICP‑OES setup and calibration: Recommended wavelengths and instrumental parameters provided; calibration curve must have linear correlation coefficient ≥ 0.995.
• Quantification: Results calculated from the calibration curve and reported in mg/kg (two decimals), using the specified formula relating sample mass, solution volume and measured concentration.
• Precision and reporting: Precision data derived from interlaboratory studies are summarized; test reports must reference ISO 24047:2021 and include sample ID, results, deviations and test date.

Applications and users

ISO 24047:2021 is aimed at laboratories and organizations involved in:

• Polymer quality control and incoming material inspection for PE and PP
• Additive monitoring and catalyst residue analysis
• Post‑reactor process studies and troubleshooting
• Regulatory compliance and environmental screening for toxic metals (Pb, Cd, etc.)
• Recyclers and compounders assessing contaminant metal levels

Typical users include analytical labs, polymer manufacturers, compounders, recyclers and regulatory testing bodies that require reliable multi‑element determination using ICP‑OES.

Related standards

• ISO 3451‑1 (plastics - determination of ash)
• ISO 648 (single‑volume pipettes)
• ISO 1042 (volumetric flasks)
• ISO 5725‑2 (precision of measurement methods)

Keywords: ISO 24047:2021, ICP‑OES, polyethylene, polypropylene, metal content, lead, cadmium, aluminium, polymer testing, ash determination.