Variation in concentration of perfluorooctanoic acid in methanol solutions during storage.

Highlights: [•] Perfluorooctanoate in methanol solutions decreased with length of storage. [•] Methyl perfluorooctanoate and methyl formate increased with length of storage. [•] Methyl perfluorooctanoate increased with increase in methyl formate. [•] Methyl perfluorooctanoate increased when perfluorooctanoate decreased. [•] Variation in the solutions stored around 5°C was smaller than that at room temp. [ABSTRACT FROM AUTHOR]