Occurrence of 4-hydroxyalkenals in rat tissues determined as pentafluorobenzyl oxime derivatives by gas chromatography-mass spectrometry.

Malondialdehyde measurements have been the major tool for studying relationships between lipid peroxidation and tissue pathology. Recently, we presented a novel gas chromatography-mass spectrometry method for direct detection of phospholipid peroxides with picogram sensitivity based on transesterification of phospholipids or triglycerides to form pentafluorobenzyl esters. Under some circumstances the reactive primary oxidation products break down. Therefore, we developed a convenient, high sensitivity method to detect more stable secondary lipid oxidation products, the 4-hydroxyalkenals. The method accomplishes a facile extraction of 4-hydroxynonenal from tissues by forming pentafluorobenzyl oxime derivatives to displace aldehydes from Schiff base linkages. 4-hydroxynonenal was found in heart, liver, adrenal, and testis from rats and was detected to the 10-100 pg level by the current method.