In the
presence of salt, the absorptions at 540 nm for
Remazol Red F-3B and 539 nm for Procion Red
MX-5B, corresponding to the monomer peaks,
show a decrease in absorption (hypochromic
shift). In addition, the soluble aggregate peak at
514 nm for Remazol Red F-3B and 513 nm for
Procion Red MX-5B shows a corresponding
increase in absorption (hyperchromic shift) rela-
tive to that of the monomer (Fig. 4)