LC/MS/MS Analysis for Restricted Chemicals in Textiles

Significance of the Topic

With growing consumer awareness and tightening global regulations, quantifying trace levels of harmful substances in textiles has become critical for environmental and human health protection. Restricted chemicals such as aromatic amines and azo dyes can migrate from fabrics, posing allergic, mutagenic and carcinogenic risks. Robust analytical methods are needed in textile manufacturing, quality control and certification schemes to ensure compliance and product safety.

Objectives and Study Overview

This work presents the development and validation of comprehensive LC–MS/MS method packages for the determination of 24 aromatic amines and 51 azo dyes in textile samples. The goals were to achieve:

• High sensitivity with limits of detection below regulatory thresholds (20 ppm for amines; 50 ppm for dyes).
• Wide dynamic ranges and excellent linearity (r2 > 0.99).
• Streamlined sample preparation by co-injection pretreatment to improve retention and reduce manual steps.

Methodology and Instrumentation

A Shimadzu Nexera X2 UHPLC system coupled to an LCMS-8045 triple quadrupole mass spectrometer was employed. Key parameters included:

• Columns: Shim-pack FC ODS, 75 × 2.0 mm (3 µm) for amines; 150 × 2.0 mm (3 µm) for dyes.
• Mobile phases: aqueous ammonium acetate (5 mM; pH 3), ammonium bicarbonate (10 mM) and acetonitrile gradients.
• Flow rate: 0.3 mL/min; column temperature: 40 °C; injection volume: 5 µL.
• ESI operated in positive/negative modes; nebulizing gas: 2.0 L/min; drying gas: 10.0 L/min; interface temp: 300 °C.
• Automated co-injection with SIL-30AC to mix sample and water for improved retention of polar analytes.

Main Results and Discussion

The methods delivered:

• Aromatic amines: linear ranges from 0.2 to 2000 ng/mL, r2 > 0.997; LODs well below 20 ppm.
• Azo dyes (44 analytes in method 1, 7 in method 2): linear ranges covering 0.1–1000 ng/mL; r2 > 0.99.
• Matrix effects for azo dyes ranged from 33 % to 168 % but were reduced to 66 %–109 % upon sample dilution.
• Co-injection pretreatment achieved consistent retention times and minimal manual error, matching manual dilution performance.

Benefits and Practical Applications

The proposed approach offers:

• Reduced sample preparation time and human error via automation.
• Comprehensive coverage of priority restricted analytes in a single workflow.
• Enhanced data reliability for regulatory compliance and quality assurance in textile production.
• Capability for high-throughput screening and batch certification tasks.

Future Trends and Opportunities

Emerging developments may include:

• Integration of column-switching systems for simultaneous multi-class contaminant analysis.
• Expansion to additional chemical classes (perfluoroalkyl substances, alkylphenols).
• Miniaturized or portable LC-MS/MS platforms for on-site textile testing.
• Advanced software tools and AI-driven data processing for real-time decision support.

Conclusion

The validated LC-MS/MS methods deliver robust, sensitive, and reliable quantitation of toxic aromatic amines and azo dyes in textiles. Automated co-injection enhances retention and reduces manual workload, while meeting stringent regulatory limits. This workflow supports efficient quality control and certification in the textile industry.

Reference

1. Chew Y.L., Xing J., Lim L.G.S., Zhan Z. Development of LC–MS/MS methods for aromatic amines in textiles. ASMS 2016 Poster TP375.
2. Chew Y.L., Xing J., Tan F.X.Q., Wee Y.H., Tuang J.L.Y., Kesuma D., Zhan Z. Quantitative analysis of azo dyes by LC–MS/MS. ASMS 2017 Poster TP727.