title: Analysis of free malondialdehyde in photoirradiated corn oil and beef fat via a pyrazole derivative.
abstract: Malondialdehyde (MA) formed in linolenic acid, linoleic acid, corn oil and beef fat upon photoirradiation was determined by gas chromatography (GC). The MA produced was reacted with methylhydrazine to give 1-methylpyrazole and was subsequently analyzed on a GC equipped with a nitrogen-phosphorus specific detector and a fused silica capillary column. MA values determined by this method correspond to free or unbound MA levels. Linolenic and linoleic acids produced 867 micrograms MA/g and 106 micrograms MA/g, respectively. Oleic and stearic acids did not produce detectable levels of MA upon photoirradiation. Amounts of MA produced after eight hour irradiations of corn oil and beef fat were 56.24 micrograms/g and 25.01 micrograms/g, respectively. Some photoreaction products in irradiated corn oil also were identified as methylhydrazine derivatives.
authors.affiliation: Department of Environmental Toxicology, University of California, Davis 95616.
authors.forename: K
authors.initials: K
authors.lastname: Umano
authors.forename: K J
authors.initials: KJ
authors.lastname: Dennis
authors.forename: T
authors.initials: T
authors.lastname: Shibamoto
mesh_terms: D002138:Calibration; D002849:Chromatography, Gas / Q000295:instrumentation; D003314:Corn Oil / Q000032:analysis*; D005223:Fats / Q000032:analysis*; D006586:Hexanes; D008314:Malonates / Q000032:analysis*; D008315:Malondialdehyde / Q000032:analysis*; D008763:Methylhydrazines / Q000032:analysis; D010782:Photolysis; D010938:Plant Oils / Q000032:analysis*
chemical_list: D005223:Fats; D006586:Hexanes; D008314:Malonates; D008763:Methylhydrazines; D010938:Plant Oils; D008315:Malondialdehyde; D003314:Corn Oil