Simplified gas chromatography of trimethylsilyl esters of C1 through C5 fatty acids in serum and urine.

All the metabolically important C1 through C5 fatty acids and lactic, pyruvic and fl-hydroxybutyric acids can be gas chromatographed surprisingly well on the common 2-meter 3% methylphenylsilicone (e.g., “OV-17”) column when a late-eluting silylating reagent such as trimethylsilylimidazole is used. In these circumstances, the trimethylsilyl esters elute in an interval that is free of the reagent and solvent interferences usually found when the more volatile preparations are used for silylations. Use of the method is demonstrated by its application to a serum from a case of isovaleric acidemia and a urine from a case of methylmalonic acid uria.