Submitted to: Journal of Chromatography A
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/24/2005
Publication Date: 7/1/2005
Citation: Ruddell, D.R., Mattheis, J.P., Fellman, J.K. 2005. Evaluation of diphenylamine derivatives in apple peel using gradient reversed-phase liquid chromatography with ulraviolet-visible absorption and atmospheric pressure chemical ionization mass selective detection. Journal of Chromatography A. 1081(2):202-209. Interpretive Summary: Superficial scald is a peel disorder of apples that can render the fruit unmarketable. Pre-storage treatment of apples with the antioxidant diphenylamine is a common practice for controlling scald. The present study evaluates a method for analyzing derivatives of diphenylamine formed in the peel during storage. The method was used to characterize and quantify diphenylamine and diphenylamine derivatives in diphenylamine-treated ‘Granny Smith’ apple peel following 6 months of low oxygen cold storage. The method was found to be useful for routinely quantifying low to high concentrations of diphenylamine and diphenylamine derivatives in apple peel. Diphenylamine content appears to be a factor limiting diphenylamine derivative formation and their recovery from apple peel was valid over a wide range of treatment concentrations.
Technical Abstract: A method was developed for extracting, identifying, and quantifying diphenylamine (DPA) derivatives in the peel of DPA-treated apples using gradient reversed-phase liquid chromatography with ultra-violet/visible absorption and atmospheric pressure chemical ionization detection (LC-UV/vis-APCIMS). Compounds routinely analyzed using this method included hydroxylated, nitrosated, nitrated, and methoxylated diphenylamine derivatives. Analysis of peel treated with 0-8 g•L**-1 DPA showed that peel DPA content was a limiting factor in derivative production and that recovery of most compounds over this range was linear.