Gas-chromatographic/mass-spectrometric identification and quantitation of tetronic and deoxytetronic acids in urine from normal adults and neonates.

Gas chromatographic/mass spectrometric/computer analyses of trimethylsilyl derivatives of urine extracts, prepared by an anion-exchange procedure, reveal the presence of several tetronic and deoxytetronic acids. Identifications were confirmed by comparing gas-chromatographic methylene unit values and mass spectrometric characteristics with those of chemically synthesized samples. In addition, several 1,4-lactones corresponding to the acids were detected in small amounts. The acids were measured in groups of adults and neonates by gas chromatographic/computer determination of peak areas and the use of calculated response factors. In urines from adults, 4-deoxythreonic, threonic, and erythronic acids were present in relatively large amounts. 4-Deoxyerythronic and 2-deoxytetronic acids were present in small to moderate amounts; 3-deoxytetronic and 2-methylglyceric acids were only trace constituents. These latter two acids, in addition to 4-deoxyerythronic, were also trace constituents of several urines from neonates but could not be detected in others. Expressed in terms of creatinine excretion, both groups excreted similar amounts of 4-deoxythreonic acid and neonates excreted significantly more 2-deoxytetronic, erythronic, and threonic acids.