Detection by fluorescence of peroxides and carbonyls in samples of arachidonic acid

1 Products of lipid peroxidation were compared in two different grades of commercially-obtained arachidonic acid. 2 The less pure 90% sample was yellow in colour, had low reactivity with 2-thiobarbituric acid and diene conjugation but high u.v. fluorescence, whereas the 99% pure sample, which was clear in colour, showed a reverse pattern of oxidation products. 3 The significance of these findings is discussed.