ISO 17812:2007

Overview

ISO 17812:2007 specifies a validated laboratory procedure for the determination of total magnesium (Mg), calcium (Ca), manganese (Mn), iron (Fe) and copper (Cu) in all types of paper, board and pulps. The method quantifies the total element content (acid‑soluble plus acid‑insoluble fractions) using atomic absorption spectrometry (AAS) or plasma emission spectrometry (ICP). Key steps include incineration, acid dissolution of the ash, destruction of acid‑insoluble residues (when present), and instrumental measurement.

Key topics and technical requirements

• Principle: Incinerate test specimen at 525 °C ± 25 °C, dissolve residue in about 6 mol/l HCl; recover both acid‑soluble and acid‑insoluble element fractions.
• Destruction of insoluble residue: Two approved options
  • Hydrofluoric acid (HF) digestion (HF 48–52%) - for silicates; requires platinum crucibles and fume hood; HF safety warning.
  • Alkali fusion with sodium carbonate/boric acid mix - melt and dissolve residue, then acidify.
• Instrumentation: Atomic absorption spectrometer (air/acetylene or nitrous oxide/acetylene burners; hollow cathode lamps for Mg, Ca, Mn, Fe, Cu) or inductively coupled plasma (ICP) emission spectrometer.
• Interference control: Use of lanthanum chloride to eliminate magnesium chemical interference in air/acetylene flame; cesium chloride may suppress Ca ionization in nitrous oxide/acetylene flame.
• Sample sizes: Typical oven‑dry test portions - 1–2 g for major elements (Mg, Ca); 5–10 g for minor elements (Mn, Fe, Cu); larger samples for trace analysis.
• Reagents, apparatus and safety: Reagent grade acids (HCl, HNO3, HF, H2SO4), platinum crucibles for HF work, muffle furnace, appropriate gas supplies (acetylene, nitrous oxide, argon), and clear warnings about hazardous chemicals and explosive gas mixtures.
• Quality control: Calibration solutions, blank determinations, duplicate testing, precision and reporting requirements are covered.

Applications

• Routine quality control and specification testing in paper, board and pulp manufacturing.
• Material characterization for coating and filler analysis, troubleshooting contamination or additive distribution.
• Regulatory and certification testing where total metal content (including elements occluded in ash) is required.
• Research and development in papermaking chemistry, recycling and material compatibility studies.

Who uses ISO 17812:2007

• Paper and board mill laboratories
• Pulp producers and recyclers
• Independent testing and certification labs
• Environmental and materials analysts working with cellulosic substrates

Related standards

• ISO 777, 778, 779, ISO 1830 - determination of acid‑soluble Ca, Cu, Fe, Mn (complementary methods)
• ISO 1762 - determination of ash/residue on ignition
• ISO 186, ISO 287, ISO 638, ISO 7213 - sampling and moisture/dry matter procedures referenced for sample handling

Keywords: ISO 17812:2007, paper testing, total magnesium, total calcium, total manganese, total iron, total copper, atomic absorption spectrometry, plasma emission spectrometry, paper board pulps, incineration, hydrofluoric acid, alkali fusion.