A process for the separation of long chain amino acid, long chain dibasic acid, alkylamine, and alkanoic acid of the following structures: from at least two of them in an alkali hydroxide hydrolysis mixture in a solvent of mixed amide derivatives of the following structures: wherein m is an integer from 0 to 10; n is an integer from 6 to 20; X is OR or NR 1 R 2, wherein OR is OH, C 1 -C 8 monohydric alcohol, or C 1 -C 8 polyhydric alcohol, and R 1 and R 2 are each independently hydrogen or C 1 -C 8 alkyl group; the process comprising: cooling the hydrolysis mixture to crystallize and to separate alkali salt of the long chain dibasic acid by means of solid-liquid separation; distilling the aqueous solution of step to recover the solvent and to recover the alkylamine; cooling the residual solution of step to precipitate and to separate alkali salt of the long chain amino acid by means of solid-liquid separation to provide a mother liquor; adding an acid to the mother liquor of step to yield the alkanoic acid; adding an acid to an aqueous solution or suspension of the alkali salt of the long chain dibasic acid of step to obtain the long chain dibasic acid; and neutralizing an aqueous solution or suspension of the alkali salt of the long chain amino acid of step with an acid to obtain the long chain amino acid. from at least two of them in an alkali hydroxide hydrolysis mixture in a solvent of mixed amide derivatives of the following structures: wherein m is an integer from 0 to 10; n is an integer from 6 to 20; X is OR or NR 1 R 2, wherein OR is OH, C 1 -C 8 monohydric alcohol, or C 1 -C 8 polyhydric alcohol, and R 1 and R 2 are each independently hydrogen or C 1 -C 8 alkyl group; the process comprising: cooling the hydrolysis mixture to crystallize and to separate alkali salt of the long chain dibasic acid by means of solid-liquid separation; distilling the aqueous solution of step to recover the solvent and to recover the alkylamine; cooling the residual solution of step to precipitate and to separate alkali salt of the long chain amino acid by means of solid-liquid separation to provide a mother liquor; adding an acid to the mother liquor of step to yield the alkanoic acid; adding an acid to an aqueous solution or suspension of the alkali salt of the long chain dibasic acid of step to obtain the long chain dibasic acid; and neutralizing an aqueous solution or suspension of the alkali salt of the long chain amino acid of step with an acid to obtain the long chain amino acid. cooling the hydrolysis mixture to crystallize and to separate alkali salt of the long chain dibasic acid by means of solid-liquid separation; distilling the aqueous solution of step to recover the solvent and to recover the alkylamine; cooling the residual solution of step to precipitate and to separate alkali salt of the long chain amino acid by means of solid-liquid separation to provide a mother liquor; adding an acid to the mother liquor of step to yield the alkanoic acid; adding an acid to an aqueous solution or suspension of the alkali salt of the long chain dibasic acid of step to obtain the long chain dibasic acid; and neutralizing an aqueous solution or suspension of the alkali salt of the long chain amino acid of step with an acid to obtain the long chain amino acid.