234 P. SOUPART 
about one-tenth of the total amount of ninhydrin-reacting material forming the 
peak, as shown by other methods!*. There are two small unidentified peaks re- 
gularly present following that of leucine. Sometimes traces of /-alanine, I- and 
3-methylhistidine and tryptophane are found. Creatinine is never apparent in 
plasma chromatograms because of its very low color factor. Some of the amino 





@ Ala F 
Val 
Thr 
Pro } 
Ser } 
Lys F 
Leu 
Tau 
AaiBA 
1 MetH 
3MetHf 
AA‘a 
NH2 Ad 
Fig. 5. Variation range and average values for normal free amino acid plasma levels. Literature 
data (shadowed area) compared to SouparRt’s data (filled circles area). Values given for glutamic 
acid and glutamine (*) are minimal values as indicated by arrow pointing upwards (see p. 222). 
Fine doted line shows the range observed by Soupart, large doted line that observed by others. 
Glutamine values are approximate since about one tenth of the glutamine peak is made of non- 
separated asparagine. 
acids present in plasma are never found in urine by this method, namely hydroxy- 
proline, proline and citrulline. 
Quantitative composition 
a) In normal healthy adults. In Table III, data from the literature relative to 
free amino acids in blood plasma have been grouped. Grouping has been done for 
data obtained through use of ion-exchange chromatography (Groups 1-6)}2, 26-89 on 
the first hand, and for data obtained by use of other methods on the other hand#!%3, 
The decreasing order of free amino acid concentration described in plasma by 
References p. 261/262 
