ISO 6101-2:2019

Overview

ISO 6101-2:2019 - Rubber - Determination of metal content by atomic absorption spectrometry - Part 2: Determination of lead content specifies an atomic absorption spectrometric (AAS) method for measuring lead (Pb) content in raw rubber and rubber products. The procedure covers sample preparation (including special treatment for halogenated rubbers), ash/digestion, solution preparation, calibration and spectrometric measurement. The method supports both flame AAS and electrothermal (graphite furnace) atomization and allows determination over a wide concentration range (no upper concentration limit), with the standard-additions technique available to improve the lower limit of detection.

Key topics and technical requirements

• Scope and applicability: Applies to raw rubber, latex and finished rubber products; suitable for a broad range of lead concentrations.
• Sample preparation:
  • Non‑halogenated rubbers: dry ashing at 550 °C ± 25 °C (refer ISO 247-1:2018).
  • Halogenated rubbers: acid mineralization (sulfuric + nitric acids), evaporation and subsequent ashing to avoid loss of volatile lead compounds.
• Dissolution and digestion:
  • Ash is boiled with ammonium acetate to dissolve lead; insoluble lead silicates converted using HCl, HNO3 and H2O2.
• Instrumentation:
  • Atomic absorption spectrometer with lead hollow‑cathode lamp; measurement wavelength 283.3 nm.
  • Graphite furnace (electrothermal atomization) may be used for enhanced sensitivity.
• Calibration and quality control:
  • Prepare calibration solutions from certified lead stock and construct a calibration graph; include blank determinations.
  • Standard‑additions method available (Annex A) to reduce detection limits and compensate for matrix effects.
• Reagents and apparatus: Lists acids, ammonium acetate, standard lead solutions, muffle furnace, pipettes, volumetric flasks and other laboratory glassware.

Applications and who uses it

ISO 6101-2:2019 is used by:

• Industrial and independent testing laboratories performing elemental analysis of rubber.
• Quality control teams at rubber manufacturers to monitor lead contamination and compliance.
• Regulatory bodies and product safety assessors verifying lead content in consumer or industrial rubber goods.
• R&D and materials scientists developing formulations or studying metal additives in elastomers.

Practical applications include batch release testing, failure analysis, compliance with chemical safety regulations, and formulation screening where metal contaminants or additives (lead) are of interest.

Related standards

• ISO 247-1:2018 - Rubber - Determination of ash - Combustion method (referenced for ashing).
• ISO 1795 - Sampling of raw rubber.
• ISO 123 - Sampling of rubber latex.
• ISO 648, ISO 1042, ISO 1772 - Laboratory glassware and crucible specifications.

Keywords: ISO 6101-2:2019, lead determination, atomic absorption spectrometry, AAS, rubber testing, lead content in rubber, graphite furnace, standard-additions, sample ashing.