Investigation of aldehydic lipid peroxidation products by gas chromatography-mass spectrometry

Lipid peroxidation (LPO) of polyunsaturated fatty acids is induced in injured or dying cells. The generated Lipid hydroperoxides readily decompose to a great variety of aldehydic compounds, which are consequently useful markers for LPO processes in biological materials. Since aldehydes are produced in tiny amounts only, their detection requires efficient separation methods combined with unambigious and specific identification techniques - e.g. separation by gas chromatography followed by identification with electron impact mass spectrometry. A great number of LPO aldehydes contains polar groups, especially carboxylic or hydroxy functions. These groups may cause decomposition when a sample is heated up in the hot injector of a gas chromatograph. Therefore such aldehydes must be protected before analysis. Derivatization enhances also volatility. Advantages and disadvantages of different methods to prepare suitable derivatives of LPO aldehydes for GC separation are discussed. The mass spectra of different derivatives are compared in order to demonstrate which ones are most useful to gain maximum information on the structure of the original aldehydes. (C) 1999 Elsevier Science BN. All rights reserved.