ISO 13365-1:2020

Overview

ISO 13365-1:2020 specifies an acetonitrile solvent extraction method followed by liquid chromatography (HPLC) to determine the total solvent-extractible content of common leather preservatives: TCMTB, PCMC, OPP and OIT. The procedure supports both UV and mass spectrometric (MS) detection and can be used to detect relevant breakdown products that protect leather from microbiological attack. The method is intended for routine quality control, regulatory compliance and laboratory testing of leather materials.

Key Topics

• Scope: Quantification of TCMTB, PCMC, OPP and OIT in leather by acetonitrile extraction and HPLC analysis.
• Sample preparation: Sampling per ISO 2418 and sample prep per ISO 4044. Wet intermediates (wet blue/white) are to be dried before testing.
• Extraction: Typical procedure uses ~1 g leather extracted with 20 ml acetonitrile in an ultrasonic bath (about 40 kHz) for 1 h ± 5 min; extract temperature rises to ~35 °C.
• Analytical system: HPLC with UV (example 275 nm) or LC-MS detection; reversed-phase C8 or C18 columns with pre-column are recommended.
• Calibration: Prepare at least four calibration solutions across an appropriate concentration range (examples given from 2 mg/l to 100 mg/l) using HPLC-grade acetonitrile and certified target-compound standards.
• Quantification limit: Method allows quantification from a minimum concentration of 10 mg/kg.
• Reporting: Results expressed as mass fraction (mg/kg), with reporting details required by the standard (reference to ISO 13365-1:2020, sample ID, detection type, any deviations, test date).

Applications

This method is directly applicable to laboratories and manufacturers needing to:

• Perform routine quality control of preservative content in finished leather and intermediates.
• Verify compliance with regulatory or customer requirements concerning preservative residues and breakdown products.
• Investigate microbiological protection efficacy linked to preservative concentration.
• Support product safety assessments and material traceability in the leather supply chain.

Practical advantages include a reproducible acetonitrile extraction protocol, compatibility with both UV and MS detection for flexibility in instrument availability, and clearly defined calibration and calculation steps for consistent reporting.

Related Standards

• ISO 2418 - Leather: sampling locations used to obtain representative test portions.
• ISO 4044 - Leather: preparation of chemical test samples before analysis.
• ISO 4684 - Leather: determination of volatile matter, required when results are recalculated on a dry-matter basis.
• ISO 3696 - Water for analytical laboratory use (reagent quality) referenced for preparation of solutions.

For chromatographic parameters and example LC/LC‑MS conditions (columns, flow rates, gradients, UV wavelength and SIM m/z values) consult Annex A of ISO 13365-1:2020. The standard provides the procedural and reporting details necessary for repeatable, traceable preservative determination in leather.