Showing papers by "Edoardo Mentasti published in 1987"
TL;DR: In this article, two different procedures were investigated and compared and compared with reference to percent recovery yield as a function of pH and effect of foreign components (surfactants, inorganic salts such as phosphates and chlorides, organic compounds such as humic acids, and NTA).
Abstract: Aluminum(III) traces have been preconcentrated through formation of anionic complexes which are retained by the anion exchanger. The ligand was Pyrocatechol Violet (PV) whose structure contains a sulfonato group (not involved in Al(III) coordination) which is responsible for the metal uptake by the resin. Two different procedures were investigated and compared. One involves the formation of Al-PV complex(es) followed by elution through a column containing the anion exchanger. The second procedure involves the loading of the PV ligand on the resin and subsequent elution of the sample. The results obtained with the two different procedures have been compared with reference to percent recovery yield as a function of pH and effect of foreign components (surfactants, inorganic salts such as phosphates and chlorides, organic compounds such as humic acids, and NTA). The first procedure was superior and has been utilized for the analysis of synthetic samples containing Al at the parts-per-billion level and for drinking water.
21 citations
TL;DR: A high-performance liquid chromatographic method for the determination of carbonyl compounds, namely aldehydes, ketones and keto acids in urine, has been developed and Matrix effects, precision, accuracy, limits of detection and structural selectivity of the method are discussed.
12 citations
TL;DR: In this article, the authors investigated the rate of oxidation by silver(II) of succinic, malic, tartaric, glycolic and lactic acids and 1,2- ethanediol, 1,3-propanediol, and 1.2-ethanediol monomethyl ether.
9 citations
TL;DR: In this paper, a series of trace metal ions, namely Al(III), Ca(II), Cd(II) and Zn(II ), were used for the uptake of celluloses containing nitrilotriacetic acid, thiourea and cysteine.
8 citations
TL;DR: The chromatographic behavior of metal complexes with 4-(2-pyridylazo)resorcinol was studied in this paper, and a satisfactory rationalization of the data was obtained together with qualitative information on the stoichiometry and charge state of the metal complexes.
Abstract: The chromatographic behaviour of Cu(II), Fe(II), Ni(II) and Co(II) complexes with 4-(2-pyridylazo)resorcinol was studied. The experimental results were very sensitive even to less obvious operational parameters like the kind of the cation (sodium or ammonium) of the phosphate salt used as buffer. The puzzling pattern of the data obtained was interpreted in terms of the equations formulated by Horvath's ‘olvophobic” theory which correlates the capacity factors of the solutes with the surface tension of the mobile phase. A satisfactory rationalization of the data was obtained together with qualitative information on the stoichiometry and charge state of metal complexes. Useful suggestions about the direction to address the experimental work in order to obtain the best results was also obtained.
8 citations
TL;DR: In this paper, the preconcentration of aluminium(III) traces in the form of anionic complexes on an anion-exchanger is described, and the ligands used to form anionic complex are hydroxide, sulphosalicylic acid, chromotropic acid and 2-(4-sulphophenyl)-1,8-dihydroxynaphthalene-3,6-disulphonic acid.
4 citations
TL;DR: In this paper, the oxidation of Ni II cyclam, cyclam and cyclam cyclan by aquasilver (II) was investigated in perchlorate media in the range [HClO 4 ] = 1-4 mol dm −3.
2 citations
TL;DR: In this paper, the oxidation of Ni II cyclam, cyclam and cyclam cyclan by aquasilver (II) was investigated in perchlorate media in the range [HClO 4 ] = 1-4 mol dm −3.
Abstract: The oxidation of Ni II cyclam, Cu II cyclam (cyclam = [18]aneN 4 ) and Cu II CT (CT = Me 6 [14]-4,11-dieneN 4 ) by aquasilver(II) has been investigated kinetically in perchlorate media in the range [HClO 4 ] = 1–4 mol dm −3 . The reaction stoichiometry indicates 1 mol of oxidant reacting with 1 mol of M(II). Stopped-flow studies indicate a single reaction pathway involving M II L + Ag 2+ with k = 2.3 × 10 5 , 3.5 × 10 5 and 1.5 × 10 4 dm 3 mol −1 s −1 for Ni II cyclam, Cu II cyclan and Cu II CT respectively, at 10 °C. While Ni III cyclam is stable enough to allow UVVis characterization, Cu III cyclam and Cu III decay by a first-order process with rate constants of 1.5 and 0.053 s −1 respectively. Reliable kinetic results could not be obtained for the oxidation of Ni II CT by silver(II), but the oxidation product does, like Ni III cyclam, have a significant lifetime.