Overview
ISO/TS 16179:2012 specifies a laboratory test method for the determination of organotin compounds in footwear materials. Applicable to all types of footwear (leather, textiles, polymers, coated materials), the Technical Specification describes sample preparation, extraction, derivatization and analysis steps to detect and quantify organotin species that may be present in footwear and footwear components.
Key topics and technical requirements
- Scope and principle: Extraction of organotins from materials with a methanol–ethanol mixture under mildly acidic conditions using tropolone as a complexing agent; conversion of non‑volatile organotin species to volatile tetra‑alkyl derivatives using sodium tetraethylborate (NaB(Et)4); detection by gas chromatography–mass spectrometry (GC‑MS).
- Target compounds: Method covers a range of organotin classes (mono-, di-, tri‑ and tetra‑substituted) such as n‑butyltin, di‑n‑butyltin, tri‑n‑butyltin, triphenyltin, di‑n‑octyltin and tetra‑n‑butyltin.
- Reagents and standards: Uses analytical‑grade solvents (methanol, ethanol, THF), tropolone, sodium acetate buffer (pH 4.5), sodium tetraethylborate, and internal standards (heptyl/propyltin species). Calibration guidance includes standard concentrations (e.g., 100–500 µg/L range) and preparation of stock and working solutions.
- Apparatus: Required equipment includes a GC‑MS with mass selective detector, inert‑atmosphere setup (glove bag) for preparing sodium tetraethylborate solutions, ultrasonic bath, centrifuge, micropipettes, analytical balance and mechanical shaker.
- Quality and safety: Safety precautions for sodium tetraethylborate (air‑sensitive, fire risk) and handling of toxic organotins (endocrine disruptors) are specified. The document provides guidance on blank preparation, calibration, quantification, and notes on detection and quantification limits (see Clauses 7.8–7.10 and Annex B on method reliability).
Applications and who uses it
- Testing laboratories performing chemical compliance testing for footwear materials.
- Footwear manufacturers and material suppliers validating raw materials and finished products for regulatory and market requirements.
- Regulatory bodies and compliance officers assessing presence of restricted organotin compounds in consumer goods.
- Environmental health & safety teams monitoring toxic organotin contamination risks in production and supply chains.
Practical uses include routine quality control, pre‑shipment testing, regulatory compliance screening and forensic or failure‑analysis investigations where organotin contamination is suspected.
Related standards
- ISO/TR 16178 - identifies which footwear materials are concerned by such determinations.
- ISO 3696 - specification for water used in analytical laboratories (referenced for reagent quality).
- Annex A of ISO/TS 16179 provides suggested GC‑MS conditions, and Annex B discusses method reliability.
Keywords: ISO/TS 16179:2012, organotin compounds, footwear materials, GC‑MS, sodium tetraethylborate, tropolone, extraction, calibration, detection limits.