Abstract:

Perfluorinated compounds (PFCs) are persistent organic compounds. PFCs are artificially prepared hydrocarbons in which hydrogen atoms are completely replaced by fluorine. PFCs have excellent thermal stability and chemical stability, high surface activity, and hydrophobic and/or oleophobic properties owing to their exceptionally strong C-F bonds, low polarizability, and weak intermolecular van der Waals interactions. Currently, PFCs and their precursors are widely used in textile production as finishing agents and surfactants. In recent years, increasing attention has been devoted to PFCs and their precursors. In many countries and regions, such as the European Union, Canada, Denmark, and the United States, directives and regulations have been issued to restrict the use of PFCs and their precursors; the number of these compounds in such lists is increasing continuously. Studies have shown that PFCs are hepatotoxic, embryotoxic, reproductive-toxic, neurotoxic, and carcinogenic, and can interfere with the endocrine system, change animal instinct behavior, and potentially induce developmental neurotoxicity in humans, especially in young children. However, there are few established methods for the simultaneous detection of multiple PFC precursors, necessitating the same particularly for textiles. In this study, a method was developed for the simultaneous determination of 11 volatile PFC precursors in textiles using gas chromatography-triple quadrupole tandem mass spectrometry (GC-MS/MS). The target compounds included four fluorotelomer alcohols (FTOHs), three fluorotelomer acrylates (FTAs), two fluorooctane sulfonamides (FOSAs), and two fluorooctane sulfonamide-ethanols (FOSEs). Studies have shown that FTOHs and FTAs are precursors of perfluorocarboxylic acid, and FOSAs are precursors of perfluorooctanesulfonic acid. Some PFC precursors are converted into perfluorocarboxylic acid and perfluoroalkyl sulfonic acid, which threaten human health and ecological security. In this study, an effective ultrasonic-assisted extraction method for the 11 target compounds was established. The effects of the extraction solvent, extraction temperature, and extraction time on the extraction efficiency were investigated. The optimum extraction conditions for the developed method were carrying out ultrasonic extraction at 70 ℃ for 60 min with methanol as the extraction solvent. Separation was performed on a VF-WAXms capillary column (30 m×0.25 mm×0.25 μm) with temperature programming, following which the target compounds were detected by GC-MS/MS in the multiple reaction monitoring (MRM) mode and quantified using the external standard method. The matrix effects of three textile matrices were also investigated. The calibration curves of the 11 volatile PFC precursors showed good linearity in the concentration range of 10-500 μg/L with correlation coefficients not less than 0.9984. The limits of detection were 0.002-0.04 mg/kg (S/N=3), and limits of quantification were 0.006-0.1 mg/kg (S/N=10). The recoveries for the 11 analytes in different textile matrix samples at three spiked levels ranged from 73.2% to 117.2% with relative standard deviations (RSDs) of 0.1%-9.4% (n=6). Through actual sample analysis, four PFC precursors were detected in the textile product samples. The method has the advantages of simple pretreatment, accurate qualitative and quantitative analysis, high sensitivity, and good reproducibility. It can be effectively used for the simultaneous determination of 11 volatile PFC precursors in textiles. The establishment of this method has theoretical and practical significance for controlling PFC precursor levels in textiles. This study offers a new testing method for mitigating risk to safety and controlling textile products. It also provides a reference for establishing testing standards for PFC precursors in textiles and other similar consumer goods.

Key words: gas chromatography-tandem mass spectrometry (GC-MS/MS), perfluorinated compound precursors, textiles