Co and Cf represent the measured metal ion concentration before
and after adding the adsorbent, respectively. To eliminate any
instrumental errors, (i) solutions were made such that Co was less
than 20 mg L−1, and (ii) the metal ion concentration before and
after adding either MOSB or ligand was analyzed. Each experiment
was conducted in duplicate. All data reported represent the mean
of the two independent experiments. The difference between the
replicate experiments was less than 10% in all cases