Identification of metabolites diagnostic for organic acidurias by simultaneous dual-column capillary gas chromatography.

To offer a procedure with increased resolution compared to packed-column gas chromatography, we developed a dual-capillary method of gas chromatography for diagnosing organic acidurias. We derivatized and injected organic acids repeatedly on two different bonded phase columns (DB-1, DB-1701) to establish a table of methylene units. Compounds in urine specimens were identified by their characteristic pair of methylene units. With this method, we are able to identify 120 metabolites in urine. Accordingly, the procedure provides a cost-effective alternative to routine gas chromatography-mass spectrometry.