Sensitive and selective quantitative analysis of Nonyl phenol ethoxylates (NPEOs) in textile samples by LC/MS/MS

Importance of the Topic

NPEOs are non-ionic surfactants widely used in detergents, waterproofing agents, adhesives and textile dyes. Their persistence and endocrine disrupting properties pose environmental and health risks. Regulatory limits in the EU restrict their concentration and create a need for reliable detection.

Study Objectives and Overview

This study aimed to develop a highly sensitive, selective and rapid LC–MS/MS method to quantify a range of nonylphenol ethoxylates in textile matrices. A simple sample preparation combined with a five-minute analysis cycle enables high throughput screening of 15 ethoxylated compounds.

Methodology and Sample Preparation

Sample extraction involved ultrasonication of approximately 1 g of textile sample in methanol at 70 °C, followed by dilution to minimize matrix effects. Textile dye samples were processed with 10 mg aliquots yielding recoveries above 90 % at 0.1 mg/L spiking levels.

Used Instrumentation

• Agilent 1290 Infinity II UHPLC system with C18 reverse-phase column.
• Agilent 6470 Triple Quadrupole LC/MS/MS with electrospray ionization in positive mode.
• Multiple Reaction Monitoring (MRM) transitions optimized for each ethoxylate species.

Main Results and Discussion

The MRM optimizer refined fragmentor voltages and collision energies, while source parameters were tuned for optimal ionization. Linearity was demonstrated from 0.1 to 5 mg/L with an R2 of 0.9982 using weighted (1/x) linear regression. The limit of quantitation (LOQ) was established at 0.1 mg/L. Repeatability tests at the LOQ level showed RSD values below 5 %. Characteristic MS chromatogram profiles facilitated clear identification and quantification of NPEO homologues.

Benefits and Practical Applications

• High-throughput analysis enabling rapid screening of multiple samples.
• Sensitivity down to 0.1 mg/L suitable for compliance monitoring with EU regulations.
• Selective MRM transitions reduce interferences in complex textile matrices.
• Simple sample preparation streamlines laboratory workflows in industrial and QA/QC settings.

Future Trends and Opportunities

Advances such as microflow UHPLC, high-resolution mass spectrometry and automated sample preparation could further enhance throughput and sensitivity. Green extraction techniques and online monitoring platforms may expand the method’s applicability to environmental and wastewater surveillance.

Conclusion

The presented LC–MS/MS method provides a robust, precise and efficient solution for the determination of nonylphenol ethoxylates in textiles. Its performance characteristics meet regulatory requirements and support routine applications in research, industry and environmental monitoring.

Reference

• ISO 18254-1: Textiles – Method for the detection and determination of alkylphenol ethoxylates (APEO) – Part 1: Method using HPLC-MS.