Chemiluminescence determination of hydroperoxides following radiolysis and photolysis of free amino acids.
Hydroperoxides were determined in selected amino acids using three free radical generating systems by a sensitive (50 pmol limit of detection) and specific high performance liquid chromatography (HPLC)/chemiluminescence method. UVB and gamma radiation produced significant hydroperoxide formation, particularly in the aromatic amino acids tyrosine and tryptophan. Hydroperoxide yield was found to be dependent on both amino acid and irradiation source. Generation of hydrogen peroxide as a by-product of irradiation caused interference with chemiluminescence detection demonstrating the need for catalase addition. Hydroperoxides were not detectable following metal-catalysed H2O2 breakdown. We suggest that metal ions could interfere with the detection of hydroperoxides by causing preferential decomposition.
Division of Chemical Pathology, Centre for Mechanisms of Human Toxicity, MRC Toxicology Unit, University of Leicester, UK.
S
S
Robinson
R
R
Bevan
J
J
Lunec
H
H
Griffiths
D000596:Amino Acids / Q000528:radiation effects*; D002374:Catalase; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D019327:Copper Sulfate; D005609:Free Radicals; D005720:Gamma Rays; D006861:Hydrogen Peroxide / Q000032:analysis*; D008163:Luminescent Measurements; D010782:Photolysis; D012680:Sensitivity and Specificity; D014466:Ultraviolet Rays
D000596:Amino Acids; D005609:Free Radicals; D006861:Hydrogen Peroxide; D002374:Catalase; D019327:Copper Sulfate