Organic acids in urine from human newborns.

The pattern of organic acids in urine from 15 normal newborn infants was investigated by gas chromatography/mass spectrometry of trimethylsilylated derivatives. The urine contains large amounts of succinic, fumaric, 2-ketoglutaric, and 3-hydroxy-3-methylglutaric acids, which are all fairly small components of urine from adults. On the other hand, hippuric acid is a small component in the urine from newborn infants, but a large component later in life. An additional number of differences can be seen. Some previously unrecognized aliphatic dicarboxylic acids were also observed, which are present to some extent in urine from adults.