Screening of per- and polyfluoroalkyl substances (PFAS) in textiles: Utilizing a new combustion-ion chromatography system for total organic fluorine (TOF) analysis

Screening of per- and polyfluoroalkyl substances (PFAS) in textiles using a new combustion-ion chromatography system (Cindion C-IC)

Significance of the topic

Textiles are a major vector for human and environmental exposure to per- and polyfluoroalkyl substances (PFAS) because these compounds are widely used to impart water, oil and stain resistance, heat protection and durability. Regulatory actions (for example California AB 1817) are imposing strict total organic fluorine (TOF) limits in textiles (100 ppm by January 2025, then 50 ppm by January 2027), and national/regional bans are being considered elsewhere. Reliable, quantitative screening methods that measure bulk organic fluorine in whole articles, rather than only surface fluorine, are therefore essential for manufacturers, regulators and analytical laboratories to demonstrate compliance and to guide material selection and remediation.

Study objectives and overview

This proof note evaluates an enhanced combustion-ion chromatography (C-IC) workflow for total organic fluorine (TOF) in textile samples implemented on the Thermo Scientific Cindion Combustion Ion Chromatography System. Objectives were to demonstrate method performance, compare results to an existing Nittoseiko C-IC platform, and highlight workflow improvements delivered by the new instrument configuration (Z-fold combustion tube, reduced furnace length, integrated Chromeleon CDS control, and a 2‑in‑1 combustion/standalone IC capability). TOF was determined by measuring total fluorine (TF) by combustion and total inorganic fluorine (TIF) by aqueous extraction and IC; TOF = TF − TIF.

Methodology

The analytical approach combined high-temperature combustion of solid textile samples with absorption of combustion effluent in water followed by suppressed ion chromatography (IC) to quantify fluoride. Key IC and combustion parameters included:

• IC separation: Dionex Inuvion IC with IonPac AS24 analytical (2 × 250 mm) and AG24 guard (2 × 50 mm).
• Eluent program: potassium hydroxide gradient from 8 mM to 75 mM (0–20 min total run time); flow 0.3 mL/min; injection 25 µL; column temperature 30 °C.
• Detection: suppressed conductivity using an ADRS 600 dynamically regenerated suppressor (2 mm, recycle mode, 56 mA).
• Combustion: Cindion combustion/absorption module with Z-fold combustion tube for staged oxygen introduction; furnace heaters at 1050 °C.
• Gas flows: primary O2 300 mL/min, turbo O2 100 mL/min, argon carrier 100 mL/min.
• Absorption: 7 mL deionized water per combustion; two-step boat program with controlled positions, waits and speeds to optimize combustion.
• TF measurement: direct combustion of textile material; TIF measurement: water extraction and direct IC injection using autosampler.
• Quality metrics: analyses performed in triplicate (n=3) with relative standard deviation (RSD) < 8% reported for TOF.

Note: Excessive sample mass can reduce combustion efficiency; if anomalously large TF peaks appear, sample weight should be reduced until results are consistent or reach lowest calibrant concentration.

Used instrumentation

• Thermo Scientific Cindion Combustion/Absorption Module (Cindion C-IC system).
• Thermo Scientific Dionex Inuvion Ion Chromatography System with Dionex AS-AP autosampler.
• Dionex IonPac AS24 analytical and AG24 guard columns.
• Dionex EGC 500 KOH eluent cartridge with CR-ATC 600 continuously regenerated anion trap column.
• ADRS 600 dynamically regenerated suppressor for suppressed conductivity detection.
• Chromeleon Chromatography Data System (single-software control of combustion and IC operations).

Main results and discussion

The method was applied to six textile samples (examples: polyester baby bib, polyurethane laminate for diapers, polyester tablecloth, ripstop nylon, and two canvas fabrics). Measured TF values spanned a wide range (from ~1 ppm up to ~375 ppm), with corresponding TIF values consistently very low (<1 ppm in most cases), indicating that the bulk of measured fluorine was organic. Calculated TOF values therefore closely tracked TF values; examples include a polyester baby bib with TF ≈ 375 ppm (TOF ≈ 375 ppm) and a ripstop nylon sample with TF ≈ 1.1 ppm (TOF ≈ 1.0 ppm).
Comparison to the legacy Nittoseiko C-IC platform showed very close agreement: TOF values obtained on the Cindion system were 100–105% of the Nittoseiko-derived values across samples, supporting equivalence of results between instruments. Triplicate analyses reported RSDs below 8%, demonstrating acceptable precision for screening and regulatory work.
The Z-fold combustion tube and shorter furnace delivered faster combustion cycles and reduced footprint without compromising combustion completeness. The integrated Chromeleon CDS simplified data management and enabled a 2‑in‑1 workflow that switches between combustion-IC and standalone IC with minimal manual intervention, improving throughput relative to multi-channel external-injection configurations that required frequent manual sample changes.

Benefits and practical applications

• Whole-sample analysis: C-IC quantifies bulk TOF independent of sample thickness, unlike surface-sensitive PIGE; this better reflects total PFAS load and potential release during use or disposal.
• Regulatory compliance: method sensitivity, precision and workflow efficiency support screening programs targeting regulatory limits such as AB 1817.
• Laboratory efficiency: Z-fold combustion design shortens combustion time and reduces bench footprint; integrated software control reduces operator steps and potential for error.
• Versatility: the 2-in-1 configuration permits both TF/TIF workflows and standalone IC analyses using the same platform and autosampler.
• Robustness: low TIF signals and consistent TF–TIF differences indicate the method reliably distinguishes inorganic fluoride background from organic fluorine content.

Future trends and potential applications

• Wider adoption of bulk TOF screening as regulations tighten will drive demand for validated, high-throughput C-IC workflows in industrial and third‑party testing labs.
• Method harmonization and inter-laboratory studies are likely to emerge to establish standard operating procedures and reporting conventions for TOF in consumer products.
• Integration with targeted PFAS speciation (LC‑MS/MS, GC‑MS) can combine bulk-fluorine screening with compound-level identification to prioritize remediation or substitution strategies.
• Instrumentation refinements—further increases in automation, reduced sample size requirements, and combined multi-element combustion-IC workflows—can expand applicability across product categories.

Conclusion

The enhanced Thermo Scientific Cindion C-IC system provides a reliable, precise and efficient workflow for TOF screening in textiles. Results for a set of representative samples agreed closely with a legacy C-IC platform (100–105% agreement, RSD < 8%), demonstrating the method's suitability for regulatory screening and quality control applications. The instrument's Z-fold combustion tube, reduced footprint, and single‑software control improve throughput and ease of use, making it a practical tool for laboratories tasked with assessing PFAS content in textiles as regulatory pressures increase. Careful control of sample mass is required to avoid combustion overload and ensure accurate TF quantitation.

References

1. Hu J, Rumachik N (2025) Application Note AN003571: Comprehensive screening of per- and polyfluoroalkyl substances (PFAS) in textiles: Utilizing combustion-ion chromatography for total organic fluorine (TOF) analysis. Thermo Fisher Scientific, Sunnyvale, CA, USA.
2. Hu J, Rumachik N (2025) Technical Note TN003853: Configuring the Thermo Scientific Cindion C-IC system for a 2-in-1 operation: Seamless switching between combustion-IC and standalone-IC with an AS-AP autosampler. Thermo Fisher Scientific, Sunnyvale, CA, USA.