Analysis of Short- and Medium- Chain Chlorinated Paraffins in Textiles and Leather Using Triple Quadrupole LC/MS

Importance of the Topic

Chlorinated paraffins (CPs) are widely used as flame retardants, plasticizers and finishing agents in textiles and leather. Short-chain (SCCPs) and medium-chain (MCCPs) chlorinated paraffins are under regulatory scrutiny due to persistence, bioaccumulation and toxicity concerns. Accurate, sensitive and robust analytical methods are essential for consumer product safety assessment and to ensure compliance with international conventions and brand restrictions.

Objectives and Study Overview

This study aimed to develop and validate a workflow using triple quadrupole liquid chromatography/mass spectrometry (LC/TQ) for quantifying SCCPs (C10–C13) and MCCPs (C14–C17) in textile and leather samples. The goals were to improve upon gas chromatography–negative chemical ionization mass spectrometry (GC-NCI-MS) by enhancing sensitivity, resolution and reducing false positives in routine testing laboratories.

Methodology and Applied Instrumentation

Sample preparation followed a modified ISO 18219-1:2021 protocol with hexane extraction, ultrasound-assisted extraction at 60 °C, concentration to dryness and redissolution in methanol with 0.22 µm PTFE filtration.

• Chromatography: Agilent 1290 Infinity II LC, ZORBAX RRHD StableBond CN column (2.1 × 100 mm, 1.8 µm), gradient elution with 5 mM ammonium acetate in water and methanol.
• Detection: Agilent 6470B triple quadrupole LC/MS with Jet Stream ESI in negative dynamic MRM mode, optimized fragmentor voltages, collision energies and source conditions via MassHunter Optimizer.
• Data Processing: Agilent MassHunter Workstation software for acquisition, quantitation and interpretation.

Key Results and Discussion

The method demonstrated excellent resolution of SCCP and MCCP congeners.

• Linearity: 0.5–5 mg/L for ΣSCCPs and ΣMCCPs, R² ≥ 0.995 for individual congeners and sum signals.
• Instrument Detection Limits (IDL): <0.004 mg/L for congeners, <0.006 mg/L for ΣSCCPs/ΣMCCPs (RSD < 5%).
• Method Detection Limits (MDL): <0.4 mg/kg in textiles and leather, <0.14 mg/kg for ΣSCCPs/ΣMCCPs (RSD < 10%).
• Recoveries and Precision: 82.5–107.4% recovery at 2 and 20 mg/kg, reproducibility RSD < 12%.

Benefits and Practical Applications

The LC/TQ workflow offers:

• Enhanced sensitivity and selectivity compared to GC-NCI-MS, reducing coelution artifacts and false positives.
• Streamlined sample preparation and robust operation with inline filters and multiwash autosampler modes.
• Applicability to routine QA/QC, compliance testing, consumer safety assessment in textile, leather and related industries.

Future Trends and Possibilities

Advancements may include high-resolution MS for isomer discrimination, further miniaturized sample prep, online extraction, and broader application to environmental and food matrices. Continued method adaptation will support evolving regulatory limits and sustainability goals.

Conclusion

The presented LC/TQ method on Agilent 1290 Infinity II and 6470B instruments provides a fast, accurate, and reliable approach for quantifying SCCPs and MCCPs in textile and leather. It meets stringent sensitivity, accuracy, and precision requirements, offering an effective alternative to GC-based methods for routine laboratory analysis.

Reference

• Guidance Document on the Analysis of Chlorinated Paraffins: Sample Preparation and Quantification in Food and Feed, v1.9, 2021.
• ISO 18219-1:2021, Leather — Determination of Chlorinated Hydrocarbons in Leather.
• ISO 22818:2021, Textiles — Determination of SCCP and MCCP by GC-NCI-MS.
• McGrath TJ, et al. Short- and Medium-Chain Chlorinated Paraffins in Polyvinylchloride and Rubber Consumer Products and Toys. Int. J. Environ. Res. Public Health. 2021;18:1069.