ISO 9198:2020 PDF

Overview

ISO 9198:2020 - Paper, board and pulp: Determination of water‑soluble sulfates - specifies a laboratory method to quantify water‑soluble sulfate ions extracted from all types of pulp, paper and board. The method uses aqueous extraction at 23 °C, followed by ion chromatography to determine sulfate concentration. The stated lower limit of determination is 20 mg SO4²⁻ per kg dry sample.

Key topics and technical requirements

• Scope: Applies to all pulp, paper and board types; intended for water‑soluble sulfates extracted under defined conditions.
• Extraction: Test portion disintegrated in 250 ml water at 23 °C ± 2 °C, soaked for about 2 hours; aliquot withdrawn for analysis.
• Analysis method: Ion chromatography with a conductivity detector; calibration with a series of standard solutions (example range 1–10 mg/L) and daily calibration checks.
• Apparatus & reagents:
  • Wet disintegrator (high‑speed mixer)
  • Ion chromatograph with known injector loop and suitable column
  • Syringe with ~0.2 µm filter or tea strainer/medium filter paper to prevent fibre carryover
  • Distilled/deionized water (conductivity