SIMPLE APPROACH FOR ANALYSIS OF PLASMA OXO-ACIDS, HYDROXY-ACIDS AND DICARBOXYLIC-ACIDS

Following deproteinization of plasma with organic solvents the superna tant was shaken with hexane and cation-exchange resin in an Eppendorf tube to remove fatty and amino acids and the medium was subjected to d irect treatment with ethyl chloroformate under catalytic influence of pyridine. A subsequent extraction of the immediately formed ethyl este rs with a drop of chloroform enabled us to subject the sample to gas c hromatographic (GC) analysis. Since ketocarboxylic acids do not requir e a preliminary oximation the total time of sample workup and analysis takes only several minutes.