Carbonyl compounds formed in sea buckthorn berry (Hippophae rhamnoides) and oil samples as a result of lipid oxidation were determined by enzymatic hydrolysis followed by derivatisation with 2, 4-dinitrophenylhydrazine and analysed by LC–UV and electrospray ionisation (ESI) tandem mass spectrometry (MS/MS). Several classes of carbonyl compounds such as saturated, unsaturated, linear and branched aldehydes and ketones, ...