Amperometric determination of lipid hydroperoxides.
A new amperometric analytical technique for measuring lipid hydroperoxides is described. The technique is based on the measurement of cathodic current due to the reduction of ferricinium ion formed as result of the oxidation of ferrocene by lipid hydroperoxides. The effects of pH and applied potential were investigated to determine the optimum pH and working potential for the determination of linoleic acid and linolenic acid hydroperoxides. The analysis, performed in pH 5.5, 0.1 M phosphate buffer and at -100 mV (vs Ag/AgCl) applied potential, responded linearly to linoleic acid hydroperoxide and linolenic acid hydroperoxide up to 1.5 and 1.2 microM, respectively. The lower detection limits were 20 nM for linoleic acid hydroperoxide and 25 nM for linolenic acid hydroperoxide. Reductants such as ascorbate and urate present in the biological samples, as well as other peroxides, did not interfere in the amperometric analyses of lipid hydroperoxides.
Mulchandani
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Chemical Engineering Department, University of California, Riverside 92521, USA.
Rudolph
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DC
D001205:Ascorbic Acid / Q000737:chemistry; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D004553:Electric Conductivity; D004563:Electrochemistry / Q000379:methods*; D004566:Electrodes; D005296:Ferrous Compounds / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D008041:Linoleic Acids / Q000032:analysis / Q000737:chemistry; D008042:Linolenic Acids / Q000032:analysis / Q000737:chemistry; D008054:Lipid Peroxides / Q000032:analysis* / Q000737:chemistry; D000075163:Metallocenes; D009942:Organometallic Compounds / Q000737:chemistry; D010084:Oxidation-Reduction; D010100:Oxygen / Q000737:chemistry; D012680:Sensitivity and Specificity; D013053:Spectrophotometry; D014527:Uric Acid / Q000737:chemistry
D005296:Ferrous Compounds; D008041:Linoleic Acids; D008042:Linolenic Acids; D008054:Lipid Peroxides; D000075163:Metallocenes; D009942:Organometallic Compounds; C025998:13-hydroperoxylinolenic acid; C008285:linoleic acid hydroperoxide; D014527:Uric Acid; D001205:Ascorbic Acid; D010100:Oxygen; C004998:ferrocene