The adsorptio
n of five N
-substituted ami
no acids with a 5-
nitroso-6-oxo pyrimidi
ne as substitue
nt o
n a commercialactivated carbo
n (AC) has bee
n studied i
n aqueous solutio
n at several pH values. The adsorptio
n processes of theseorga
nic compou
nds have bee
n a
nalyzed o
n the basis of the electrolytic behavior of the adsorbates. I
n all cases, theadsorptio
n process is highly irreversible due to stro
ng
-
i
nteractio
ns betwee
n the are
ne ce
nters of the AC a
nd thepyrimidi
ne residue of the adsorbates. This i
nteractio
n is co
nsiste
nt with XPS data a
nd HOMO-LUMO theoreticalcalculatio
ns. The adsorptio
n of these orga
nic compou
nds provides a
new route for the fu
nctio
nalizatio
n of the ACsurface with carboxyl groups. I
n additio
n, the adsorptio
n capacity of the AC/orga
nic compou
nd systems for Cu(II)io
ns i
n aqueous solutio
n has bee
n studied at differe
nt pH values. These systems show a
n i
ncrease of the adsorptio
ncapacity for Cu(II) compared to the AC, which is related to the AC fu
nctio
nalizatio
n with carboxyl groups due tothe adsorbed orga
nic compou
nds.