title: Photodegradation of folic acid in aqueous solution.
abstract: A study of the photodegradation of folic acid by ultraviolet radiation in aqueous solution has been made. Folic acid is photolysed by an apparent first-order kinetics and the log k-pH profile shows a gradual decrease in rate in the pH range 2.0-10.0. The profile indicates the appearance of three steps which reflect the participation of different ionic species of folic acid (pKa(1) 2.3, pKa(2) 8.3) in the photolysis reaction. The rate of photodegradation varies from 0.1550 x 10(-3) min(-1) (pH 10.0) to 5.04 x 10(-3) min(-1) (pH 2.5) in the pH range studied. The photolysis of folic acid shows that it is degraded to pterine-6-carboxylic acid and p-amino-benzoyl-L-glutamic acid. A maximum yield of these products is obtained at 3-8 h, depending upon the pH. An HPLC method has been used for the assay of folic acid and its degradation products.
authors.affiliation: Department of Chemistry, University of Karachi, Pakistan.
authors.forename: M J
authors.initials: MJ
authors.lastname: Akhtar
authors.forename: M A
authors.initials: MA
authors.lastname: Khan
authors.forename: I
authors.initials: I
authors.lastname: Ahmad
mesh_terms: D002851:Chromatography, High Pressure Liquid; D005492:Folic Acid / Q000737:chemistry* / Q000528:radiation effects*; D005971:Glutamates / Q000032:analysis / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D010782:Photolysis / Q000528:radiation effects*; D011621:Pteridines / Q000032:analysis / Q000737:chemistry; D012996:Solutions / Q000737:chemistry / Q000528:radiation effects; D014466:Ultraviolet Rays; D014867:Water / Q000737:chemistry
chemical_list: D005971:Glutamates; D011621:Pteridines; D012996:Solutions; C405202:pterine-6-carboxylic acid; D014867:Water; D005492:Folic Acid; C011398:4-aminobenzoylglutamic acid