ISO 6101-4:2022

Overview

ISO 6101-4:2022 specifies an atomic absorption spectrometric (AAS) method for the determination of manganese (Mn) content in rubber. The method applies to raw rubber and rubber products with Mn content above 0.5 ppm; lower concentrations can be measured by adjusting test‑portion mass or solution concentrations, or by using the standard additions technique to lower the limit of detection. The procedure covers sample ashing, dissolution, calibration and spectrometric measurement using a manganese hollow‑cathode lamp (measurement wavelength 279.5 nm).

Key topics and technical requirements

• Scope & applicability: Intended for raw natural/synthetic rubber, latex and finished rubber products; representative sampling is referenced to ISO 1795 and ISO 123.
• Sample preparation:
  • Test portions typically 1–5 g (products) or 5–10 g (raw rubber), milled or finely cut.
  • Ashing in a muffle furnace at 550 °C ± 25 °C for raw rubber or 950 °C ± 25 °C for carbon‑black‑rich products (per ISO 247‑1).
  • Organic destruction, possible re‑ashing of carbonaceous residue and volatilization of silicates with sulfuric/hydrofluoric acids where needed.
• Dissolution reagents: Dilute hydrochloric acid (2% HCl) or dilute nitric acid (1.6% HNO3) for final sample solutions; detailed reagent preparation included.
• Measurement:
  • Aspirate dissolved sample into an AAS fitted with acetylene/air burner and manganese hollow‑cathode lamp (279.5 nm).
  • Alternative: electrothermal atomization (graphite furnace) where applicable.
  • Calibration graph preparation, blank determinations and dilution procedures are specified.
• Quality elements: Number of determinations, expression of results, and precision data (Annex B). Annex A describes the standard additions method for improved detection.
• Apparatus & glassware: Muffle furnace, AAS, volumetric flasks, pipettes and specified crucibles per ISO laboratory glassware standards.

Applications and users

ISO 6101-4:2022 is used by:

• Rubber manufacturers and compounders for quality control and raw‑material screening.
• Independent testing laboratories performing metal contamination analysis in rubber products.
• R&D teams and failure‑analysis labs investigating material properties influenced by trace metals.
• Regulatory and compliance bodies assessing product safety or environmental release of metals.

Practical uses include monitoring Mn contamination from catalysts or additives, ensuring product consistency, supporting corrective actions in production, and meeting contractual or regulatory specifications.

Related standards

Normative references include:

• ISO 247‑1 (ash determination)
• ISO 1795 (sampling raw rubber)
• ISO 123 (latex sampling)
• ISO 1042, ISO 648, ISO 835 (laboratory glassware)
• ISO 1772 (crucibles)

Keywords: ISO 6101-4:2022, manganese determination, atomic absorption spectrometry, AAS, rubber testing, metal content, standard additions, sample ashing.