Landaas S, Jakobs C
Clin Chim Acta. 1977 Aug 1;78(3):489-93. doi: 10.1016/0009-8981(77)90082-1.
Examination of urine samples by capillary column gas chromatography and mass spectrometry showed the presence of 2-hydroxyisovaleric acid together with trace amounts of the three branched-chain 2-keto acids in five patients with lactic and ketoacidosis. None of these compounds was detected in urine from healthy controls.