Overview
EN ISO 11936:2023 - Leather: Determination of total content of certain bisphenols specifies an analytical method to measure the total solvent-extractible content of four bisphenols in leather: bisphenol A, B, F and S. Published by CEN and aligned with ISO/IULTCS guidance, the method uses methanol extraction (ultrasonic bath) and liquid chromatography (LC) with detection by LC‑MS/MS, LC‑MS, LC‑UV, LC‑DAD or LC‑FLD. The procedure can be extended to other bisphenols after laboratory validation.
Key topics and technical requirements
- Scope: Quantification of solvent‑extractible bisphenol A, B, F and S in leather samples; method applicable to other bisphenols if validated.
- Extraction principle: Ultrasonic extraction in methanol at (60 ± 5) °C; aliquots can be analysed directly without additional cleanup.
- Instrumentation: Liquid chromatography coupled with one of:
- Single quadrupole MS (LC‑MS)
- Triple quadrupole MS/MS (LC‑MS/MS)
- UV detector (LC‑UV)
- Diode array detector (LC‑DAD)
- Fluorescence detector (LC‑FLD)
- Calibration and internal standards: Multi‑level calibration (examples given from 20 µg/l to 1000 µg/l). Use of mass-labelled internal standards (e.g., BPA‑D8, BPA‑D16, BPF‑D10, BPS‑D8) is recommended for LC‑MS(/MS) to reduce matrix effects.
- Apparatus & reagents: Ultrasonic bath with temperature control, syringe filters (0.2 µm), LC vials and LC‑grade methanol; water grade per ISO 3696.
- Documentation: Method includes procedures for sample preparation, calculation (with/without internal standard), precision data and reporting requirements. Informative annexes give example LC operating parameters and method precision (Annexes A–D).
Practical applications
- Quality control in leather manufacturing to monitor residual monomers/impurities from tanning agents.
- Laboratory testing for product safety and chemical content analysis using standardized LC methods.
- Regulatory and conformity testing where measurement of bisphenols in consumer articles or industrial leather products is required.
- Research and troubleshooting to identify sources of bisphenol contamination (e.g., impurity in synthetic tanning agents).
Who should use this standard
- Accredited testing laboratories performing chemical analyses on leather.
- Leather manufacturers and tanneries implementing in‑house QC for chemical residues.
- Product safety professionals and regulators assessing chemical content in leather goods.
- Environmental and toxicology labs concerned with endocrine‑active substances in materials.
Related standards
- ISO 2418 - Position and preparation of leather specimens
- ISO 4044 - Preparation of chemical test samples (leather)
- ISO 3696 - Water for analytical laboratory use
Keywords: EN ISO 11936:2023, leather testing, bisphenol A, bisphenol B, bisphenol F, bisphenol S, LC‑MS/MS, LC‑UV, solvent extraction, leather quality control, CEN, IULTCS.