SIST EN ISO 11210:2023 PDF

Overview

EN ISO 11210:2023 - Jewellery and precious metals - Determination of platinum - Gravimetry using ammonium chloride specifies a gravimetric laboratory method for accurately determining platinum content in homogeneous precious‑metal materials. The method is suitable for finenesses preferably between 50 and 999 ‰ (parts per thousand) by mass. For fineness above 999 ‰ the standard points to spectroscopic methods by difference (e.g. ISO 15093). EN ISO 11210:2023 supersedes the 2016 edition and aligns the method with related standards for jewellery and precious‑metal testing.

Key topics and technical requirements

• Principle: dissolve sample in aqua regia, precipitate platinum as diammonium hexachloroplatinate using ammonium chloride, ignite to metallic platinum (“platinum sponge”) and weigh gravimetrically.
• Silver removal: where silver is present, separate as silver chloride (AgCl) before platinum precipitation.
• Co‑precipitated elements: re‑dissolve platinum sponge and check for alloying elements (e.g. by ICP‑OES) and apply corrections.
• Reagents and apparatus: specifies analytical‑grade reagents (HCl, HNO3, aqua regia, NH4Cl, saturated NH4Cl solution), muffle furnace (≥900 °C), reduction apparatus, porcelain crucibles, ashless filter paper (≈3 μm), and an analytical balance with 0.01 mg readability.
• Sampling and preparation: sampling according to ISO 11596; flattening samples, weighing representative portions (targeting ~250 mg–1 g Pt); controlled evaporation cycles without drying; temperature control to avoid Pt reduction and re‑oxidation steps if needed.
• Quality and reporting: calculation, repeatability provisions (Clause 9), and required test‑report contents are defined. Safety and handling guidance is included for corrosive reagents and reducing gases.

Applications and users

• Used by assay offices, jewellery manufacturers, precious‑metal refineries, testing laboratories, and regulatory authorities for determining platinum fineness and composition.
• Practical for quality control of jewellery alloys and other precious‑metal products, material certification, dispute resolution, and process control in refining.
• Suitable as one of the recommended methods for determining fineness in jewellery alloys covered by ISO 9202.

Related standards

• ISO 15093 - spectroscopy methods by difference for very high fineness.
• ISO 9202 - determination of fineness in jewellery alloys (recommended methods).
• ISO 11490 - harmonized procedures referenced in the revision.
• ISO 11596 - sampling of precious‑metal articles.

Keywords: EN ISO 11210:2023, platinum determination, gravimetry using ammonium chloride, jewellery testing, precious metals analysis, diammonium hexachloroplatinate, platinum sponge, aqua regia, ICP‑OES.