Estimation of branched-chain alpha-keto acids in blood by gas chromatography.
Plasma or whole blood is treated with o-phenylenediamine dihydrochloride in phosphoric acid under conditions found spectrophotometrically to give maximum yields of the quinoxalinols. The quinoxalinols are extracted and, after removing phosphoric acid, etc., silylated with bis-trimethylsilyltrifluoracetamide in acetonitrile. Other solvents caused instability of the trimethylsilyl(TMS)-quinoxalinols. Gas chromatography on a packed column of trifluoropropyl silicone gave good separation of the TMS-quinoxalinols from one another and from other substances derived from blood. Some representative values for normal arterial and venous human and canine plasma are reported.
D000818:Animals; D055598:Chemical Phenomena; D002621:Chemistry; D002849:Chromatography, Gas; D004285:Dogs; D006801:Humans; D007651:Keto Acids / Q000097:blood*; D010655:Phenylenediamines; D011810:Quinoxalines / Q000032:analysis
D007651:Keto Acids; D010655:Phenylenediamines; D011810:Quinoxalines; C034193:1,2-diaminobenzene