DETERMINATION OF HYDROPEROXIDES AND STRUCTURES BY HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY WITH POSTCOLUMN DETECTION WITH DIPHENYL-1-PYRENYLPHOSPHINE

A high-performance liquid chromatographic method, using post-column de tection with diphenyl-1-pyrenyl-phosphine (DPPP), was developed for th e quantitative and qualitative determination of isomeric lipid hydrope roxides (OOH). The OOH eluted from a normal-phase column were passed t hrough a photodiode array detector and then mixed with DPPP solution i n a reaction coil heated at 80 degrees C. DPPP oxide formed by the rea ction with OOH was determined by monitoring the fluorescence intensity at 380 nm and excitation at 352 nm. The conjugated diene OOH (13-cis, trans- and 9-cis, trans-OOH) and nonconjugated OOH (12-cis-trans- and 10-cis,trans-OOH) from photosensitized oxidation of methyl linoleate w ere determined in a molar ratio of 31:29:19:21, respectively. However, only the two conjugated hydroperoxides were detected by ultraviolet a bsorption at 234 nm. Further applications were carried out for the det ermination of OOH of methyl oleate and methyl linolenate. This method proved to be useful for the determination of the OOH containing both c onjugated and nonconjugated diene structures.