Zhipu Xuebao (Mar 2023)
Simultaneous Determination and Exposure Assessment of 12 Volatile Per- and Polyfluoroalkyl Substances in Infant and Child Textiles
Abstract
Per- and polyfluoroalkyl substances (PFAS) are a large class of organic compounds, in which all or part of the hydrogen atoms in the alkyl-chain are replaced by fluorine, and many PFAS are used globally in chemicals, leather textile, paper, packaging and other industrial and consumer goods production fields. Many studies have shown that PFAS possesses hepatic and metabolic toxicity, reproductive and developmental toxicity, immunotoxicity, and so on. Therefore, the use of PFAS in textiles has been restricted by lots of regulations or standards world widely, such as the International Ecological Textile Standard (STANDARD 100 by OEKO-TEX®), the Restricted Substances List (RSL) of the American Apparel & Footwear Association (AAFA) and the REACH regulations of EU. However, there is still lack of simultaneous determination method for various volatile PFAS in relevant standards. In this study, a method of gas chromatography-mass spectrometry (GC-MS) was developed for the simultaneous determination of 12 volatile PFAS in infant and child textiles, including four fluorotelomer alcohols (FTOHs), three fluorotelomer acrylates (FTAs), three perfluorooctane sulfonamides (FOSAs) and two perfluorooctane sulfonamidoethanols (FOSEs). The redissolve solvent was optimized, and the extraction efficiencies for different extraction solvents, extraction volumes, extraction times, extraction temperature and time were compared. 20 mL Acetonitrile was selected as extraction solvent, and the sample was extracted twice by ultrasonic at 60 ℃ for 30 min each time, then the combined supernatants were concentrated by rotary evaporation. Finally, the targets were separated by DB-5MS column and detected at selected ion monitor (SIM) mode, and quantified by external standard method. The results showed that 4∶2 FTOH and the other 11 volatile PFAS had good linear relationship in the range of 20-5 000, 10-5 000 μg/L, respectively, and the correlation coefficients (R2) were not less than 0.998. The limits of quantification (LOQs) were 0.03-0.07 mg/kg. The recoveries of 12 PFAS were 71.9%-113.6% under the two spiked levels (levels at the LOQ and the limit content of relevant standards), and the relative standard deviations (RSDs) were 1.2%-12.8% (n=6). The method has the advantages of simple pretreatment, accurate qualitative and quantitative determination, high sensitivity, and good repeatability. The actual samples were divided into two groups and determined by this method. One group included 53 pieces of textile fabrics with certain waterproofness that were tested daily in the laboratory. Some of these textile fabrics have cartoon patterns, which may be used for making children’s clothing. The other group included 26 pieces of infant and child clothes purchased from online stores. The results showed that the positive rate of volatile PFAS in textile fabrics was high. FTOHs and FTAs were detected, and their concentrations were in the range of 0.08-276.41 mg/kg. FOSAs were not detected in the samples. The textile fibers with PFAS detected were mainly polyester. Volatile PFAS were not detected in the randomly purchased infant and child cloth products, which might be mainly because they didn’t have waterproofs. The skin exposure model proposed by the European Chemical Agency was used to assess exposure risks. The mixed exposure of various PFAS in textiles was calculated by the relative potency factor (RPF), which was converted into the equivalent of PFOA, and compared with the safety threshold given by the US Environmental Protection Agency and the European Food Safety Agency. The results showed that the risk of direct health hazards to infants and children from the exposure of detected target substances was low. The method has reference value for the control of volatile PFAS risk substances in baby textiles.
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