Determination of extractable perfluorooctanoic acid (PFOA) in water, sweat simulant, saliva simulant, and methanol from textile and carpet samples by LC/MS/MS

Methods were developed to quantify the amount of perfluorooctanoic acid (PFOA) extracted from textile and carpet samples through contact with water, methanol, and sweat and saliva simulants using LC/MS/MS. The limit of quantitation (LOQ) for samples extracted in water and sweat simulant is 1 ppb (ng PFOA (g sample)−1) while the limits of quantitation for samples extracted in saliva simulant and methanol were 3 ppb and 2.5 ppb, respectively. Method validation results are provided for a polyester control textile sample that was extracted in water on two different days by different analysts, which gave an overall recovery of 103% and standard deviation of 5.3% for 30 analyses. However, for routine application of these methods to a large number of sample sets differing in chemical and physical compositions, a complete validation for each sample type is not practical or possible since control samples for fortifications are often not available. Instead, suitable analytical methods and acceptance criteria are described which ensure accurate PFOA quantitation in each of the solvent extract types. During routine use of these methods, post-extraction spike recoveries for the different sample types and solvents are 100 ± 15% using a dual isotopically labeled 13C-PFOA internal standard to correct for matrix effects. A comparison of extraction solvent versus time using a wrist action shaker for textile and carpet samples demonstrates that the total extractable amount of PFOA is similar for each of the solvent types. However, as expected the rate of extraction in water and simulants is significantly less than that of methanol. Finally, a comparison of 2 h and 24 h wrist action shaker extractions with a 1.5 h pressurized fluid extraction (PFE) in methanol reveals that the 24 h wrist action shaker yields the highest results. The 2 h wrist action shaker results are similar to those of the 1.5 h PFE extraction.