Isotachophoretic analysis of serum for aspartic acid, asparagine, glutamic acid and glutamine

Free amino acids and other low molecular weight components were separated from samples of human blood serum by membrane ultrafiltration. The filtrates were analyzed for aspartic acid, asparagine, glutamic acid and glutamine by isotachophoresis, without further treatment. For comparison, analyses were also performed by ion-exchange chromatography. The results of the analyses from both methods are of similar magnitude. General trends were noted in the samples analyzed. The values for aspartic acid and asparagine were lower, by both methods, than normal values. Also, the values, that were determined by isotachophoresis, were generally higher than those obtained from ion-exchange chromatography. The results are sufficient to demonstrate the applicability of the method to the analysis of the two amino acids and their amides in serum.