Identification and estimation of some uncommon diamino acids

Application of the amino acid analyzer is described for the separation, identification, and estimation of several uncommon dibasic amino acids that are eluted with a 0.35 m, pH 5.28, sodium citrate buffer between lysine and ammonia, namely, 2,5-diaminohexanoate, threo- and erythro-3,5-diaminohexanoate, 3,6-diaminohexanoate (β-lysine) and 2,4-diaminopentanoic acid. Conditions are also given for estimating d- and l-β-lysine as their l-glutamyl peptides, and for estimating the enantiomers of threo- and erythro-3,5-diaminohexanoate as the l-glutamyl derivative of the corresponding lactams.