Chiral separation of amino acids in urine specimens from patients with inherited metabolic disorders by achiral gas chromatography

An efficient method is described for the enantioseparation of urinary amino acids to determine their absolute configurations. It involves two-phase extractive ethoxycarbonylation in alkaline aqueous solution with subsequent extraction after acidification. The resulting derivatives of amino acids are converted to volatile diastereomeric esters or amides for the direct analysis by gas chromatography (GC) on achiral dual-columns with different polarities. The present method was applied to urine specimens from patients with inherited metabolic disorders. In this study, the usefulness for the chiral separation of diagnostic amino acids will be discussed.