Determination of very-long-chain fatty acids in plasma by a simplified gas chromatographic-mass spectrometric procedure.

The concentration of very-long-chain fatty acids (VLCFA) (straight chain, more than 22 carbon atoms) in plasma or in cultured fibroblasts is one of the most important diagnostic criteria for the diagnosis of the peroxisomal disorders. A sensitive method for VLCFA assay in plasma, using small sample volume and a simplified procedure, is described. After adequate extraction and derivatization, methyl esters of VLCFA are separated, identificated and quantified by gas chromatography-mass spectrometry (GC-MS). The method is sensitive, reproducible, accurate and relatively simple. GC-MS equipment used for routine organic acid analysis can be used.