Behaviour of tyrosine and cystine on paper chromatograms and their quantitative estimation.

Tyrosine and cystine have been found to
streak on paper chromatograms with almost
all solvents. The phenotnenon has been
traced to their sparing solubility in the aqueous
as well as the solvent phases. Employtnent of
amino acid solutions and of solvent systems
rendered sufficiently acidic or alkaline helps to
secure compact spots and adequate separations.
Unidimensional development with pH 1.0.
buffered phenol on similarly buffered paper is
satisfactory for the quantitative estimation of
the acids.