The remaining phenolic acids (m-hydroxybenzoic, p-hydroxyphenylacetic and 3,4-dihydroxymandelic acids) as well as other acids (benzoic, cinnamic, mandelic (2-hydroxy-2-phenylacetic) and piperylonic (3,4-methylenedioxybenzoic) acids) were identified using the mass spectral library provided by the GC–MS supplier