HPLC Analysis of Lipid Peroxides. III.

Abstract

Naturally occurring glycerophospholipids which are mainly composed of phosphatidyl choline (PC), phosphatidyl ethanolamine (PE), phosphatidyl inositol (PI) and phosphatidyl serine (PS) were able to be separated into their molecular species by reversed phase HPLC. The separation was achieved on a silica C1 (Fine SIL C1) column, using a mobile phase of hexane/2-propanol/water (6/8/1 vol/vol/vol) at a flow rate of 1.0mL/min., and the eluants were monitored simultaneously at 210nm of a multi-channel UV detector.Peroxidized molecular species of soybean phospholipids such as PC-30 in which PC was contained ca. 30%, PC-70, PC-95 and PE could be selectively identified by monitoring with the detector at 235nm, and good linear relationships (Y=1.01×10-3X, correlation coefficient r=0.9810.991 for all samples used here) were observed between the ratio of peak area at 235nm of the peroxides to that of all peaks at 210nm on the chromatogram and peroxide value (POV) of sample phospholipid in the range of 050meq/kg.On the basis of this linear relationship, POVs of each molecular species of autoxidized phospholipids originated from soybean, linseed and egg yolk were determined, and reliable values could be obtained by this newly developed method having good reproducibility and the lowest detection limits of 0.5 nano-equivalents of peroxides in comparison with the potentiometric POV method which employed as a standard method to measure the POV of samples.