The Experts below are selected from a list of 291 Experts worldwide ranked by ideXlab platform
Brett Paull - One of the best experts on this subject based on the ideXlab platform.
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separation of selected transition metals by capillary chelation ion chromatography using acetyl Iminodiacetic Acid modified capillary polymer monoliths
Journal of Chromatography A, 2012Co-Authors: Aine Moyna, Pavel N Nesterenko, Damian Connolly, Ekaterina P Nesterenko, Brett PaullAbstract:Abstract Capillary housed laurylmethacrylate- co -ethylene dimethacrylate (LMA- co -EDMA) polymer monoliths were fabricated, functionalised with varying amounts of vinyl azlactone, followed by immobilisation of Iminodiacetic Acid (IDA), forming a range of acetyl-Iminodiacetic Acid (AIDA) functionalised monoliths, applied to the chelation ion chromatographic separation of selected transition and heavy metals. A number of monoliths of varying length and ligand density were prepared, resulting in increased cation retention and chromatographic resolution on those displaying the highest capacity. Ligand density and related column capacity were confirmed visually using scanning capacitively coupled contactless conductivity detection (sC 4 D) techniques. Column temperature studies to determine retention mechanism and the effect of temperature on the retention of Mn(II), Cd(II) and Cu(II) was investigated, showing an increase in retention with increased temperature for Cd(II) and Cu(II), whilst a decrease in retention was obtained for Mn(II). Isocratic capillary chelation ion chromatographic separations of Mn(II), Cd(II) and Cu(II) were obtained, with dual peak detection demonstrated using combined on-column C 4 D detection and UV–Visible detection following the post-capillary column reaction of the eluted metals with 4-(2-pyridylazo) resorcinol (PAR).
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ion exchange properties of monolithic and particle type Iminodiacetic Acid modified silica
Journal of Separation Science, 2004Co-Authors: Edel Sugrue, Pavel N Nesterenko, Brett PaullAbstract:A 10 cm silica monolith has been modified with Iminodiacetic Acid (IDA) groups and characterised for its selectivity toward alkali, alkaline earth, and selected transition metal cations. Physical characterisation of the modified monolith found non-homogeneous modification along the length of the monolith, although sufficient capacity was achieved to facilitate significant retention of alkaline earth and transition/heavy metal ions over a range of eluent pH and ionic strength conditions. For alkaline earth and transition/heavy metal ions, selectivity of the 10 cm IDA monolith closely matched that seen with a 25 cm IDA modified silica gel particle packed column, although the separation of alkali metal ions was noticeably poorer on the monolithic column. Peak efficiencies for most metal ions were of a similar order for both column types, except for Zn(II), which showed significant peak broadening on the IDA monolithic column.
Pavel N Nesterenko - One of the best experts on this subject based on the ideXlab platform.
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separation of selected transition metals by capillary chelation ion chromatography using acetyl Iminodiacetic Acid modified capillary polymer monoliths
Journal of Chromatography A, 2012Co-Authors: Aine Moyna, Pavel N Nesterenko, Damian Connolly, Ekaterina P Nesterenko, Brett PaullAbstract:Abstract Capillary housed laurylmethacrylate- co -ethylene dimethacrylate (LMA- co -EDMA) polymer monoliths were fabricated, functionalised with varying amounts of vinyl azlactone, followed by immobilisation of Iminodiacetic Acid (IDA), forming a range of acetyl-Iminodiacetic Acid (AIDA) functionalised monoliths, applied to the chelation ion chromatographic separation of selected transition and heavy metals. A number of monoliths of varying length and ligand density were prepared, resulting in increased cation retention and chromatographic resolution on those displaying the highest capacity. Ligand density and related column capacity were confirmed visually using scanning capacitively coupled contactless conductivity detection (sC 4 D) techniques. Column temperature studies to determine retention mechanism and the effect of temperature on the retention of Mn(II), Cd(II) and Cu(II) was investigated, showing an increase in retention with increased temperature for Cd(II) and Cu(II), whilst a decrease in retention was obtained for Mn(II). Isocratic capillary chelation ion chromatographic separations of Mn(II), Cd(II) and Cu(II) were obtained, with dual peak detection demonstrated using combined on-column C 4 D detection and UV–Visible detection following the post-capillary column reaction of the eluted metals with 4-(2-pyridylazo) resorcinol (PAR).
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ion exchange properties of monolithic and particle type Iminodiacetic Acid modified silica
Journal of Separation Science, 2004Co-Authors: Edel Sugrue, Pavel N Nesterenko, Brett PaullAbstract:A 10 cm silica monolith has been modified with Iminodiacetic Acid (IDA) groups and characterised for its selectivity toward alkali, alkaline earth, and selected transition metal cations. Physical characterisation of the modified monolith found non-homogeneous modification along the length of the monolith, although sufficient capacity was achieved to facilitate significant retention of alkaline earth and transition/heavy metal ions over a range of eluent pH and ionic strength conditions. For alkaline earth and transition/heavy metal ions, selectivity of the 10 cm IDA monolith closely matched that seen with a 25 cm IDA modified silica gel particle packed column, although the separation of alkali metal ions was noticeably poorer on the monolithic column. Peak efficiencies for most metal ions were of a similar order for both column types, except for Zn(II), which showed significant peak broadening on the IDA monolithic column.
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isocratic separation of lanthanides and yttrium by high performance chelation ion chromatography on Iminodiacetic Acid bonded to silica
Journal of Chromatography A, 1998Co-Authors: Pavel N Nesterenko, Phil JonesAbstract:Abstract The variation of chromatographic retention of lanthanide ions and yttrium on a column packed with Iminodiacetic Acid bonded to silica was studied. The influence of nitric Acid concentration, ionic strength of the eluent and temperature as well as complexing agents (diglycolic, maleic Acid) was investigated. It was shown that with nitric Acid as eluent in the presence of 0.5 M–1.0 M potassium nitrate the retention of the lanthanides under increased temperature is defined mainly by the stability of the corresponding surface complexes with Iminodiacetic Acid functional groups. The combination of increased ionic strength of the eluent (0.5 M potassium nitrate) with increased temperature of the chromatographic column (65°C) allowed, under optimal concentration of nitric Acid (1.6·10−2 M), the isocratic separation of 14 lanthanide ions and yttrium in 65 min.
Friedrich Birger Anspach - One of the best experts on this subject based on the ideXlab platform.
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Silica-based metal chelate affinity sorbents I. Preparation and characterization of Iminodiacetic Acid affinity sorbents prepared via different immobilization techniques
Journal of Chromatography A, 1994Co-Authors: Friedrich Birger AnspachAbstract:Iminodiacetic Acid (IDA) was immobilised on silica supports using either activated chromatographic supports or silanes carrying IDA in ω-position to silicium. Through reaction of IDA with glycidoxypropyltrimethoxysilane (GLYMO) before immobilization, a new and simple method is introduced which provides a metal chelate affinity sorbent of both high capacity for Cu(II) (28 μmol/ml) and almost identical chromatographic characteristics to soft gel metal chelate affinity sorbents. By immobilization of IDA through n-alkyl spacers exclusive of an epoxy group a different chemical neighborhood to the chelator is obtained. These metal chelate sorbents demonstrated higher capacities for Cu(II) (39 μmol/ml). The selectivity for lysine was higher, for histidine lower, compared to epoxy-immobilized IDA chelates. It is concluded that the β-hydroxyl group, evolved during reaction with epoxy groups, is integrated with the metal chelate, thus forming a N-(hydroxyethyl)Iminodiacetic Acid (HEIDA). The most distinct chromatographic behaviour was observed with CDI-immobilised IDA chelates, which displayed higher selectivity for Acidic amino Acids than common IDA chelates. © 1994.
Petr Jandik - One of the best experts on this subject based on the ideXlab platform.
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ion chromatography of transition metals on an Iminodiacetic Acid bonded stationary phase
Journal of Chromatography A, 1990Co-Authors: G K Bonn, S Reiffenstuhl, Petr JandikAbstract:Abstract A stationary phase synthesized by covalent binding of Iminodiacetic Acid to a porous silica support was investigated for the separation of transition metals by ion chromatography. Eluents containing carboxylic Acids either alone or in combination with stronger complexing agents were studied in order to examine the elution mechanisms of alkali, alkaline earth and transition metal ions. It was found that both complexation reactions and ion-exchange mechanisms occurred, their rate being governed by the stability of metal complexes. These investigations were used to find optimum conditions for the determination of transition metal ions in alkali and alkaline earth metal-rich matrices, e.g., sea water.
Hiroko Wada - One of the best experts on this subject based on the ideXlab platform.
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adsorption mechanism of trivalent metal ions on chelating resins containing Iminodiacetic Acid groups with reference to selectivity
Analytical Chemistry, 1997Co-Authors: Akio Yuchi, Teruo Sato, Yuka Morimoto, And Haruyuki Mizuno, Hiroko WadaAbstract:The adsorption equilibria of seven trivalent metal ions (M3+: Sc3+, Y3+, La3+, Fe3+, Al3+, Ga3+, and In3+) on chelating resins containing Iminodiacetic Acid groups (-LH2) were studied. Adsorption curves, measured under the conditions of metal ions in excess against chelating groups, directly indicated the metal-to-ligand ratio of the complexes formed in the resin phase. Iron and group 13 metal ions were adsorbed as (-L)2HM, while group 3 metal ions were adsorbed as (-L)3H3M and (-L)2HM. The adsorption constants for (-L)2HM found for all the metal ions were well correlated with the formation constants of iminodiacetate complexes in aqueous solutions. The actual adsorption of group 3 metal ions was significantly enhanced beyond that expected from this correlation because of the formation of (-L)3H3M. This is why the selectivity in the adsorption of trivalent metal ions differs from that in the complexation of iminodiacetate in aqueous solutions. The effects of anions and the number of Iminodiacetic Acid gr...
