Poison in textiles - Quantitative determination of organotin

Importance of the topic

The widespread use of organotin compounds such as tributyltin in plastics stabilization, antifouling paints and biocidal applications poses significant health and environmental concerns. Media reports of organotin residues in textiles triggered public awareness and highlighted the need for sensitive analytical methods to ensure consumer safety and regulatory compliance.

Objectives and Study Overview

This study describes the development of a quantitative GC-MS method using the Shimadzu QP2010 to determine organotin compounds in textile samples. The aim is to achieve detection limits and accuracy compatible with industry and eco-label threshold values.

Methodology

• Sample extraction: 2 g of textile refluxed with 0.1 % acidified methanol for 30 minutes
• Derivatization: Ethylation using sodium tetraethylborate in n-hexane at pH 4.5 for 3–4 hours
• Cleanup: Silica gel column (EN DIN 38407-13D) with hexane; final volume adjusted to 200 µL in n-decane
• Calibration: Internal standard method with organotin chlorides for each alkylation degree

Instrumentation Used

• Shimadzu GCMS-QP2010 quadrupole mass spectrometer
• DB-5 capillary column (30 m × 0.25 mm × 0.25 µm)
• Injector at 260 °C, splitless injection (100 kPa, 2 min)
• Oven program: 60 °C (2 min), ramp 8 °C/min to 160 °C, then 20 °C/min (2 min)
• Ion source 250 °C, interface 320 °C, SIM mode

Main Results and Discussion

The method achieved a routine detection limit of 0.5 ng/L (absolute) and 0.1 ng/L under optimal conditions, corresponding to 0.05 mg/kg in textiles—meeting QUL and Oeko-Tex Standard 100 values for tributyltin. Calibration curves were linear from 0.1 to 10 ng/µL. Ethylated TBT spectra exhibited well-defined fragments despite isotope complexity, demonstrating robust quantification of mono-, di- and tributyltin species.

Benefits and Practical Applications

• Enables quality control in textile and consumer goods industries
• Ensures compliance with eco-label and safety standards
• Supports environmental and food-chain monitoring
• Adaptable to diverse organotin analytes and matrices

Future Trends and Potential Applications

• Incorporation of tandem MS for improved selectivity and sensitivity
• Automation of sample preparation for higher throughput
• Exploration of non-derivatization techniques with soft ionization
• Extension to additional organometallic pollutants and evolving regulations

Conclusion

The Shimadzu GCMS-QP2010 method offers a sensitive, reliable and standards-compliant approach for quantifying organotin compounds in textiles, supporting routine QA/QC and regulatory surveillance.