Perfluorononanoic acid; 50 µg/mL in MeOH with 4 mole eq. NaOH; 1 mL

Perfluorononanoic acid (PFNA) at a concentration of 50µg/mL in methanol (MeOH) with 4 molar equivalents of sodium hydroxide (NaOH) is commonly used as an analytical standard in environmental testing, particularly for detecting per- and polyfluoroalkyl substances (PFAS). The addition of NaOH helps prevent esterification of PFNA in methanol, maintaining the stability of the standard.