1977 Volume 26 Issue 6 Pages 375-379
Aliphatic amines (dimethylamine, ethylamine, and diethylamine) and aromatic amines (aniline, N, N-dimethylaniline, diphenylamine and p-aminobenzoic acid) were titrated conductimetrically with ethylenediamine tetraacetic acid (EDTA) in dimethylsulfoxide (DMSO). EDTA was very soluble in DMSO and its solution was used as standard. A sharp inflection point were observed for the titration of aliphatic amines with EDTA at the mole ratio of 4:1. On the other hand, no inflection point was observed for aromatic amines with EDTA. The titration of aliphatic amines is possible in the presence of aromatic amines DL-serine, DL-methionine, and DL-threonine and hydrochloric acid salts of L-glutamic acid, glycine, L-cystine and L-aspartic acid were also titrated with EDTA and the observed inflection points was also 4:1. In the mixture of amino acid and aliphatic amine, the end point corresponding to the amount of aliphatic amine was observed.
