Figure 2.
Stability of perfluoroalkyl ether carboxylic acids (PFECAs): (a) mono-ether PFECAs, (b) HFPO acid homologues, and (c) multi-ether PFECAs in acetonitrile (ACN) at room temperature (20.2°C). Curves describe results of first-order kinetic models, and the corresponding rate constants are given in Table 2. HFPO-DA is plotted in both panels (a) and (b) for comparison. To facilitate comparability, all analyte concentrations were normalized to the initial concentration (Ct/C0). Error bars represent standard deviations of duplicate measurements. See Figure S1 for compound structures.