title: The use of formic acid in carrier gas. Rapid method for identification and determination of phytanic acid by gas chromatography-mass spectrometry-chemical ionization.
abstract: A rapid gas chromatographic method to determine phytanic acid in plasma from Refsum's disease is described. After a brief alkaline hydrolysis of lipids, the biological sample is directly injected into a glass pre-column; an acid carrier gas (formic acid in nitrogen) is used to displace the long-chain fatty acids from their sodium salts and from their binding to proteins. Formic acid introduced through the column may also be used as a reagent gas for chemical ionization in combined gas chromatography--mass spectrometry; fatty acids (C14 to C18:2 and phytanic acid) are easily identified by their M + 1 (base peak) and M - 17 peaks. The described procedure is also suitable for studying normal fatty acids from plasma lipids.
mesh_terms: D004537:Eicosanoic Acids / Q000097:blood*; D005230:Fatty Acids, Nonesterified / Q000097:blood; D005561:Formates; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods; D006801:Humans; D008055:Lipids / Q000097:blood; D010831:Phytanic Acid / Q000097:blood*; D012016:Reference Values; D012035:Refsum Disease / Q000097:blood*
chemical_list: D004537:Eicosanoic Acids; D005230:Fatty Acids, Nonesterified; D005561:Formates; D008055:Lipids; D010831:Phytanic Acid