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Poly(methyl methacrylate-methacryloylamidoglutamic acid) beads (average diameter 150-200 µm) were prepared by copolymerizing methyl methacrylate (MMA) with methacryloylamidoglutamic acid (MAGA). Poly(MMA-MAGA) beads were characterized by swelling and surface area studies, scanning electron microscopy, and elemental analysis. These porous beads with a swelling ratio of 36.4% and containing 696 µmol of MAGA/g were used for heavy-metal removal involving cadmium, mercury, and lead. Poly(MMA-MAGA) beads have a specific surface area of about 67.8 m 2 /g. Metal adsorption results were found to be a function of solution properties (i.e., medium pH and metal concentration) and the types of metals to be adsorbed. We have obtained adsorption capacities as 29.9 mg/g (149 µmol/g) for Hg(II), 28.2 mg/g (250 µmol/g) for Cd(II), and 65.2 mg/g (314 µmol/g) for Pb(II). The adsorption capacities on an observed molar basis were in the order of Pb(II) > Cd(II) > Hg(II). Adsorption of heavy-metal ions from synthetic wastewater was also studied. The adsorption capacities are 22.4 mg/g for Hg(II), 24.2 mg/g for Cd(II), and 52.6 mg/g for Pb(II) at 0.5 mmol/L initial metal concentration. Of course, depending on the desired goals, the beads containing metal could be regenerated for appropriate disposal. Our results suggest that poly(MMA-MAGA) beads can be good metal adsorbers and have great potential applications in environmental protection.

The examination of the dissociation constants of sulfonamides is essential in drug-design studies and in explaining the biopharmaceutical properties of substances. The dissociation constants of ten common human and veterinary antibiotics, namely, sulfadiazine, sulfamerazine, sulfamethoxazole, sulfathiazole, sulfamonomethoxine, sulfamethoxypyridazine, sulfadimethoxine, sulfafurazole, sulfadoxine, and sulfaquinoxaline, in water and in 15 %, 23 %, and 30 % (v/v) acetonitrile−water mixtures were determined by a UV/pH titration method and correlated with the Kamlet and Taft solvatochromic parameters, π*, α, and β. Kamlet and Taft’s general equation was reduced to two terms by combined factor analysis and target factor analysis in these mixtures: the independent term and polarity/polarizability π*, which is a solvatochromic parameter. Further, the quasi-lattice quasi-chemical (QLQC) theory of preferential solvation has been applied to quantify the preferential solvation by water of electrolytes in acetonitrile−water mixtures.

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