UPLC-MS/MS Determination of 4 Long-Chain Perfluoroalkyl Acids in Textiles

The sample of 0.500 g was extracted ultrasonically with methanol of 10 mL for 30 min at 50℃. The extract of 4 mL was taken and 5 mmol·L^-1 ammonium acetate solution of 6 mL was added. The solutions were mixed and filtered. Four long-chain perfluoroalkyl acids (PFuDA, PFDoA, PFTriDA and PFTeDA) in the above solution were determined by UPLC-MS/MS, and ACQUITY UPLC BEH C₁₈ column was used as the stationary phase and the mixture of 5 mmol·L^-1 ammonium acetate solution and methanol in different volume ratios was used as the mobile phase for gradient elution. Negative electrospray ion source and multi reaction monitoring mode were adopted in MS analysis, and cone voltages were 50, 20, 28, 24 V, respectively. As shown by the results, Linear relationships between values of peak area and mass concentration of 4 long-chain perfluoroalkyl acids were found in the range of 1.00-100 μg·L^-1, with detection limits (3S/N) in the range of 0.4-0.6 μg·L^-1. Test for recovery was made by standard addition method, giving results in the range of 86.8%-96.4%, with RSDs (n=7) ranged from 3.7% to 9.7%.