The second test was conducted to verify if the precipitation of
proteins occurred and whether the colorant solubility in the supernatant
increased; low volumes of RK and RZN reagents and ten mL
of water:ammonium hydroxide (9.1) were added at the pre-treatment
and solubility stages, respectively. Although the precipitation
was effectively observed, the resulting solution remained turbid,
indicating that the colorants had not been totally dissolved and,
as a result, the solid material had not completely precipitated