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Chelating Capacity (chelating + capacity)
Selected AbstractsSynthesis and Metal-Complexation Properties of a New Hydroxypyrimidinone-Functionalized SepharoseEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 3 2005M. Alexandra Esteves Abstract The 1-hydroxy-2-(1H)-pyrimidinone derivative 4-(3-aminopropylamino)-1-hydroxy-2-(1H)-pyrimidinone (HOPY-PrN) was synthesized and its acid-base and complexation properties towards a set of metal ions (FeIII, AlIII, and ThIV) were studied by potentiometry and spectrophotometry. The ligand was further immobilized in an epoxy-activated sepharose by chemical coupling through the aminoalkyl pendent group with the aim of improving its sequestering capacity for residual amounts of metals. The new hydroxypyrimidinone-functionalized sepharose shows a high chelating capacity for metal ions in the pH range 3,8, thus suggesting good perspectives for potential environmental applications. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005) [source] Preparation of a heterogeneous hollow-fiber affinity membrane having a mercapto chelating resin and its recovery of Hg2+ cationsJOURNAL OF APPLIED POLYMER SCIENCE, Issue 1 2008Bing Wang Abstract A kind of heterogeneous hollow-fiber affinity filter membrane with a high chelating capacity for Hg2+ was prepared by phase separation with blends of a mercapto chelating resin and polysulfone as the membrane materials, N,N -dimethylacetamide as the solvent, and water as the extraction solvent. The adsorption isotherms of the hollow-fiber affinity filter membrane for Hg2+ were determined. The heterogeneous hollow-fiber affinity filter membrane was used for the adsorption of Hg2+ cations through the coordination of the mercapto group and Hg2+ cations, and the effects of the morphology and structure of the affinity membrane on the chelating properties were investigated. The chelating conditions, including the chelating resin grain size, pH value, concentration of the metallic ion solution, mobile phase conditions, and operating parameters, had significant effects on the chelating capacity of the hollow-fiber affinity filter membrane. The results revealed that the greatest chelating capacity of the hollow-fiber affinity filter membrane for Hg2+ was 1090 ,g/cm2 of membrane under appropriate conditions, and the adsorption isotherms of Hg2+ could be described by the Langmuir isotherm. The dynamic chelating experiments indicated that the hollow-fiber affinity membrane could be operated at a high feed flow rate and that large-scale removal of Hg2+ could be realized. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 [source] In vitro toxicity of several dithiocarbamates and structure,activity relationshipsJOURNAL OF APPLIED TOXICOLOGY, Issue 6 2002N. Segovia Abstract Dithiocarbamates (DTCs) are chemicals featuring a great chelating capacity. The toxicological study of DTCs is very important in view of their relatively simple synthesis and wide array of sanitary and industrial applications. In this study, the toxicity of some of the more recently synthesized DTCs is determined using an extremely simple bioassay, described in previous studies, based on the inhibition of growth of Escherichia coli (IGEC). The lowest-observed-effect concentration (LOEC), the median effective concentration (EC50) and no-observed-effect concentration (NOEC) of the following sodium dithiocarbamates was determined: N -benzyl- N -methyldithiocarbamate·2H2O, N -benzyl- N -isopropyldithiocarbamate·3H2O, N -benzyl- N -ethyldithiocarbamate·2H2O, N -butyl- N -methyldithiocarbamate·2H2O, N,N -dibenzyldithiocarbamate·2H2O and N -benzyl-2-phenethyldithiocarbamate·4H2O. Our results showed N,N -dibenzyl-DTC to be the least toxic of the tested substances, with an EC50 value of 1269.9 µg ml,1, whereas N -butyl- N -methyl-DTC and N -benzyl- N -methyl-DTC, with respective EC50 values of 14.9 µg ml,1 and 23.5 µg ml,1, were the most toxic. Regression analysis showed, through exponential models, that the degree of toxicity of this group of substances correlated with the molecular weight of the compound, the molecular weight of the smallest chemical radical linked to the dithiocarbamate group and the number of benzene rings present in the molecule. The consideration of these models allows us to establish that in general terms the toxicity of DTCs decreases exponentially with a greater molecular weight and the number of benzene rings. Copyright © 2002 John Wiley & Sons, Ltd. [source] | ||||||||||