Fig.2
Chromatograms of the DDB derivatives in normal human: (A) serum and (B) urine. Peaks: 1=α-ketoglutaric acid; 2=pyruvic acid; 3=p-hydroxyphenylpyruvic acid; 4=α-ketobutyric acid; 5=α-ketovaleric acid;6 =α-ketoisovaleric acid; 7=α-ketoisocaproic acid; 8=phenylpyruvic acid; 9=α-ketocaproic acid;10=α-keto-b-methylvaleric acid;11=glyoxylic acid; 12=unidentified; 13=DDB. Column: Radial-Pak C18 (5μm ; 100 x 8 mm I.D.). Mobile phase: methanol-acetonitrile-40 mM phosphate buffer (pH 7.0) (60:40:95, v/v). Flow-rate:I.2 ml/min.