Long-chain aliphatic fatty acids and phytanic acid simultaneously measured by dual-column capillary chromatography.

A method is described for simultaneously measuring long-chain aliphatic fatty acids and phytanic acid in plasma, for the diagnosis of disorders associated with peroxisomal defects, eliminating the need for two separate chromatographic runs to resolve all of the analytes. In addition, the simultaneous, dual-column analysis allows confirmation of the identity and quantity of the individual fatty acids, thus adding a degree of certainty when results are used for interpretation and differential diagnosis of the many clinical manifestations of peroxisomal defects.