HIGHLY SENSITIVE FLOW-INJECTION ANALYSIS OF LIPID HYDROPEROXIDES IN FOODSTUFFS

Lipid hydroperoxides in oils and foods were measured by a flow injecti on analysis system with high sensitivity and selectivity. After sample injection, lipid hydroperoxides were reacted with diphenyl-1-pyrenylp hosphine (DPPP) in a stainless steel coil, then the fluorescence inten sity of DPPP oxide, that was produced by the reaction, was monitored. By this method, trilinolein hydroperoxide showed good linearity betwee n 0.4 and 79 pmol and their detection limits were 0.2 pmol (signal-to- noise ratio=3). The method made it possible to inject samples at 2-min intervals. There was a good agreement of the amounts of lipid hydrope roxides in oils and foods between by the batch method with DPPP and by the proposed method (coefficient of correlation: r=0.999; n=21; perox ide value=0.09-167 meq/g). With this method, the calibration graph of trilinolein hydroperoxide was useful for all samples tested.