Overview
ISO 17070:2015 - Leather - Chemical tests - Determination of tetrachlorophenol-, trichlorophenol-, dichlorophenol-, monochlorophenol‑isomers and pentachlorophenol content specifies a laboratory method to detect and quantify chlorinated phenols (CP) in leather. The method covers PCP (pentachlorophenol), TeCP (tetrachlorophenol), TriCP (trichlorophenol), DiCP (dichlorophenol), MoCP (monochlorophenol) isomers, their salts and esters. The procedure uses steam‑distillation, liquid–liquid extraction, acetylation (derivatization), and gas chromatography (GC) with either an electron capture detector (ECD) or a mass selective detector (MSD).
Key topics and requirements
- Scope and analytes: Target analytes include PCP, tetrachlorophenols, trichlorophenols, dichlorophenols and monochlorophenols (isomer‑specific).
- Sample preparation: Follow ISO 2418 and ISO 4044 guidance for sampling and sample size; grind or cut leather to ~2–3 mm pieces.
- Analytical principle: Steam‑distillation of the leather sample, extraction into n‑hexane, acetylation of chlorophenols to chlorinated phenyl acetates, and GC analysis (ECD or MSD).
- Standards and calibration: Use a chlorinated phenol mix as an external standard and tetrachloroguaiacol (TCG) as an internal standard. Prepare calibration/derivatization blanks the same way as samples. Required recovery: >90%.
- Equipment and reagents: Includes steam‑distillation apparatus, mechanical shaker (>200 cycles/min), GC‑ECD/MSD, analytical balance, n‑hexane, acetic anhydride, triethylamine, K2CO3, anhydrous Na2SO4.
- Safety: Derivatization with acetic anhydride and organic solvent extraction must be done in a fume hood.
- Results reporting: Report CP concentrations as mass fraction in mg/kg (rounded to one decimal). Optional dry‑matter correction using ISO 4684 volatile matter data.
Applications and users
- Quality control in leather manufacturing: Verify raw and finished leather comply with internal limits or legal thresholds for chlorinated phenols.
- Regulatory testing and compliance: Support compliance with environmental and chemical safety regulations that restrict PCP and other chlorophenols in consumer products.
- Forensic and environmental labs: Characterize contamination in leather goods and investigate sources of chlorinated phenols.
- Third‑party testing laboratories and research institutions: Routine method for laboratories accredited to international standards (e.g., ISO 17025) performing chemical testing of leather.
Related standards
- ISO 2418 - Sampling location for leather
- ISO 4044 - Preparation of chemical test samples (leather)
- ISO 4684 - Determination of volatile matter (dry‑matter corrections)
- ISO 3696 - Water for analytical laboratory use
Keywords: ISO 17070:2015, leather chemical tests, chlorinated phenols, pentachlorophenol (PCP), gas chromatography (GC‑ECD/MSD), acetylation, steam‑distillation, leather testing.