The Experts below are selected from a list of 438 Experts worldwide ranked by ideXlab platform
Nicholas C. Frampton - One of the best experts on this subject based on the ideXlab platform.
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Mechanistic aspects of nitrate-selective electrodes with immobilsed ion exchangers in a Rubbery Membrane
The Analyst, 2003Co-Authors: Jim Braven, Les Ebdon, Nicholas C. Frampton, Thierry Le Goff, D. Scholefield, Peter G. SuttonAbstract:The response mechanism of nitrate ion selective electrodes (ISEs) containing covalently bound quaternary ammonium salt sensor molecules has been investigated using 15N tracer studies, ion exchange measurements and surface analysis by electron microscopy using energy dispersive X-ray analysis. The ISEs were shown to operate by surface ion exchange mechanism with no involvement of ion diffusion though the Membrane. Ion selectivity was shown to be dependent on a solvent mediator increasing Membrane surface permeability towards nitrate allowing ion exchange to occur. A new sub-category of classification for electrodes of this type is proposed.
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nitrate selective electrodes containing immobilized ion exchangers within a Rubbery Membrane with controlled cross link density
Analyst, 1991Co-Authors: Les Ebdon, Jim Braven, Nicholas C. FramptonAbstract:A range of ion-selective electrodes have been produced for the determination of nitrate using polymeric Membranes containing immobilized quaternary ammonium salts as the ion exchanger. The use of acrylonitrile–butadiene copolymer with a 19% acrylonitrile content as the polymer matrix produced electrodes with excellent [graphic omitted] values of 1.1 × 10–3 but with short lifetimes. Varying the cross-link density of the Membranes from 0.6 × 10–5 to 11.0 × 10–5 mol cross-link cm–3 did not produce any significant difference in electrochemical behaviour. Two novel ion exchangers, triallyloctylammonium bromide and triallyldodecylammonium bromide, were successfully synthesized and fabricated into Membranes. Triallyloctylammonium bromide gave the longest lifetime Membranes and the best electrode was fabricated from the acrylonitrile–butadiene copolymer with a 50% acrylonitrile content and 6.5% m/m triallyloctylammonium bromide, 7.2% m/m dicumyl peroxide and 39.7% 2-nitrophenyl octyl ether. The electrode had a lifetime in excess of 500 d and the response to nitrate was Nernstian in the range 1 × 10–1–1 × 10–4 mol dm–3 of nitrate. The limit of detection was 4.5 × 10–5 mol dm–3 and the selectivity coefficient for chloride over nitrate [graphic omitted] was 5.3 × 10–3. The immobilized ion exchanger Membrane electrode offered superior lifetime and mechanical strength.
Peter G. Sutton - One of the best experts on this subject based on the ideXlab platform.
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Mechanistic aspects of nitrate-selective electrodes with immobilsed ion exchangers in a Rubbery Membrane
The Analyst, 2003Co-Authors: Jim Braven, Les Ebdon, Nicholas C. Frampton, Thierry Le Goff, D. Scholefield, Peter G. SuttonAbstract:The response mechanism of nitrate ion selective electrodes (ISEs) containing covalently bound quaternary ammonium salt sensor molecules has been investigated using 15N tracer studies, ion exchange measurements and surface analysis by electron microscopy using energy dispersive X-ray analysis. The ISEs were shown to operate by surface ion exchange mechanism with no involvement of ion diffusion though the Membrane. Ion selectivity was shown to be dependent on a solvent mediator increasing Membrane surface permeability towards nitrate allowing ion exchange to occur. A new sub-category of classification for electrodes of this type is proposed.
Jim Braven - One of the best experts on this subject based on the ideXlab platform.
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Mechanistic aspects of nitrate-selective electrodes with immobilsed ion exchangers in a Rubbery Membrane
The Analyst, 2003Co-Authors: Jim Braven, Les Ebdon, Nicholas C. Frampton, Thierry Le Goff, D. Scholefield, Peter G. SuttonAbstract:The response mechanism of nitrate ion selective electrodes (ISEs) containing covalently bound quaternary ammonium salt sensor molecules has been investigated using 15N tracer studies, ion exchange measurements and surface analysis by electron microscopy using energy dispersive X-ray analysis. The ISEs were shown to operate by surface ion exchange mechanism with no involvement of ion diffusion though the Membrane. Ion selectivity was shown to be dependent on a solvent mediator increasing Membrane surface permeability towards nitrate allowing ion exchange to occur. A new sub-category of classification for electrodes of this type is proposed.
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nitrate selective electrodes containing immobilized ion exchangers within a Rubbery Membrane with controlled cross link density
Analyst, 1991Co-Authors: Les Ebdon, Jim Braven, Nicholas C. FramptonAbstract:A range of ion-selective electrodes have been produced for the determination of nitrate using polymeric Membranes containing immobilized quaternary ammonium salts as the ion exchanger. The use of acrylonitrile–butadiene copolymer with a 19% acrylonitrile content as the polymer matrix produced electrodes with excellent [graphic omitted] values of 1.1 × 10–3 but with short lifetimes. Varying the cross-link density of the Membranes from 0.6 × 10–5 to 11.0 × 10–5 mol cross-link cm–3 did not produce any significant difference in electrochemical behaviour. Two novel ion exchangers, triallyloctylammonium bromide and triallyldodecylammonium bromide, were successfully synthesized and fabricated into Membranes. Triallyloctylammonium bromide gave the longest lifetime Membranes and the best electrode was fabricated from the acrylonitrile–butadiene copolymer with a 50% acrylonitrile content and 6.5% m/m triallyloctylammonium bromide, 7.2% m/m dicumyl peroxide and 39.7% 2-nitrophenyl octyl ether. The electrode had a lifetime in excess of 500 d and the response to nitrate was Nernstian in the range 1 × 10–1–1 × 10–4 mol dm–3 of nitrate. The limit of detection was 4.5 × 10–5 mol dm–3 and the selectivity coefficient for chloride over nitrate [graphic omitted] was 5.3 × 10–3. The immobilized ion exchanger Membrane electrode offered superior lifetime and mechanical strength.
Les Ebdon - One of the best experts on this subject based on the ideXlab platform.
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Mechanistic aspects of nitrate-selective electrodes with immobilsed ion exchangers in a Rubbery Membrane
The Analyst, 2003Co-Authors: Jim Braven, Les Ebdon, Nicholas C. Frampton, Thierry Le Goff, D. Scholefield, Peter G. SuttonAbstract:The response mechanism of nitrate ion selective electrodes (ISEs) containing covalently bound quaternary ammonium salt sensor molecules has been investigated using 15N tracer studies, ion exchange measurements and surface analysis by electron microscopy using energy dispersive X-ray analysis. The ISEs were shown to operate by surface ion exchange mechanism with no involvement of ion diffusion though the Membrane. Ion selectivity was shown to be dependent on a solvent mediator increasing Membrane surface permeability towards nitrate allowing ion exchange to occur. A new sub-category of classification for electrodes of this type is proposed.
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nitrate selective electrodes containing immobilized ion exchangers within a Rubbery Membrane with controlled cross link density
Analyst, 1991Co-Authors: Les Ebdon, Jim Braven, Nicholas C. FramptonAbstract:A range of ion-selective electrodes have been produced for the determination of nitrate using polymeric Membranes containing immobilized quaternary ammonium salts as the ion exchanger. The use of acrylonitrile–butadiene copolymer with a 19% acrylonitrile content as the polymer matrix produced electrodes with excellent [graphic omitted] values of 1.1 × 10–3 but with short lifetimes. Varying the cross-link density of the Membranes from 0.6 × 10–5 to 11.0 × 10–5 mol cross-link cm–3 did not produce any significant difference in electrochemical behaviour. Two novel ion exchangers, triallyloctylammonium bromide and triallyldodecylammonium bromide, were successfully synthesized and fabricated into Membranes. Triallyloctylammonium bromide gave the longest lifetime Membranes and the best electrode was fabricated from the acrylonitrile–butadiene copolymer with a 50% acrylonitrile content and 6.5% m/m triallyloctylammonium bromide, 7.2% m/m dicumyl peroxide and 39.7% 2-nitrophenyl octyl ether. The electrode had a lifetime in excess of 500 d and the response to nitrate was Nernstian in the range 1 × 10–1–1 × 10–4 mol dm–3 of nitrate. The limit of detection was 4.5 × 10–5 mol dm–3 and the selectivity coefficient for chloride over nitrate [graphic omitted] was 5.3 × 10–3. The immobilized ion exchanger Membrane electrode offered superior lifetime and mechanical strength.
Thierry Le Goff - One of the best experts on this subject based on the ideXlab platform.
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Mechanistic aspects of nitrate-selective electrodes with immobilsed ion exchangers in a Rubbery Membrane
The Analyst, 2003Co-Authors: Jim Braven, Les Ebdon, Nicholas C. Frampton, Thierry Le Goff, D. Scholefield, Peter G. SuttonAbstract:The response mechanism of nitrate ion selective electrodes (ISEs) containing covalently bound quaternary ammonium salt sensor molecules has been investigated using 15N tracer studies, ion exchange measurements and surface analysis by electron microscopy using energy dispersive X-ray analysis. The ISEs were shown to operate by surface ion exchange mechanism with no involvement of ion diffusion though the Membrane. Ion selectivity was shown to be dependent on a solvent mediator increasing Membrane surface permeability towards nitrate allowing ion exchange to occur. A new sub-category of classification for electrodes of this type is proposed.
