A new solid-state mercury ion-selective electrode was prepared by directly coating the surface of a glassy carbon electrode with tetrahydrofuran solution containing PVC, 25,27-dihydroxy-26,28- bis[(1′-naphthalene) se...A new solid-state mercury ion-selective electrode was prepared by directly coating the surface of a glassy carbon electrode with tetrahydrofuran solution containing PVC, 25,27-dihydroxy-26,28- bis[(1′-naphthalene) selenopropoxy] calix[4]arene, dioctyl phthalate and potassium tetrakis(4-chlorophenyl) borate. The response of the electrode is linear with a good Nernstian slope of 31.5 mV/decade over an Hg 2+ ion concentration range of 5.0×10 -9—5.0×10 -2 mol/L and a detection limit of 1.0×10 -9 mol/L. The response time to achieve a 95% steady potential for Hg 2+ detection is less than 30 s, and the electrode is suitable for use within the pH range of 2—4. The selectivity for Hg 2+ relative to several alkali, alkaline earth, transition and heavy metal ions is good. The mechanism of the potential response of this system was also discussed.展开更多
<正> In this Paper, PVC membrane Selective clectrodes are prepared for theophylline which are based on its ion-pair complexes with hexadecylt- rioctylammonium iodide (HTOA) , hexadecyltributyl-ammonium iodide (H...<正> In this Paper, PVC membrane Selective clectrodes are prepared for theophylline which are based on its ion-pair complexes with hexadecylt- rioctylammonium iodide (HTOA) , hexadecyltributyl-ammonium iodide (HTBA), hexadeeyltriophenylphosphonium iodide(HTPP), triphenyloctylphosphonium leoide(TPOP) and tri(p-tolyl) butylphosphonium iodide(TPTBP).The effects of the nature of associate counterions, the plastieizers and their concentrations in the membrane phase have been studied. The electrode based on theophylline-HTOA membrane has a sub-Nernstian response range from 2.0×10~2—6.3×10~(-5)mol/L,with an average slope of 48.0mV/pC. The limit of detection is 8.7×10~(-6)mol/L. The electrode responses were not affected by pH in the range 10-12. The potentiometric selectivity coefficients of various common inorganic and organic ions including those which are similar to theophylline in structure were determined. The Na_2CO_3-Na_2B_4O_7 buffer of pH 11 is selected as the background solution for potentiometric measurements. The electrode was used for determining the theophylline in pharmaceutical preparations with satisfactory results.展开更多
文摘A new solid-state mercury ion-selective electrode was prepared by directly coating the surface of a glassy carbon electrode with tetrahydrofuran solution containing PVC, 25,27-dihydroxy-26,28- bis[(1′-naphthalene) selenopropoxy] calix[4]arene, dioctyl phthalate and potassium tetrakis(4-chlorophenyl) borate. The response of the electrode is linear with a good Nernstian slope of 31.5 mV/decade over an Hg 2+ ion concentration range of 5.0×10 -9—5.0×10 -2 mol/L and a detection limit of 1.0×10 -9 mol/L. The response time to achieve a 95% steady potential for Hg 2+ detection is less than 30 s, and the electrode is suitable for use within the pH range of 2—4. The selectivity for Hg 2+ relative to several alkali, alkaline earth, transition and heavy metal ions is good. The mechanism of the potential response of this system was also discussed.
文摘<正> In this Paper, PVC membrane Selective clectrodes are prepared for theophylline which are based on its ion-pair complexes with hexadecylt- rioctylammonium iodide (HTOA) , hexadecyltributyl-ammonium iodide (HTBA), hexadeeyltriophenylphosphonium iodide(HTPP), triphenyloctylphosphonium leoide(TPOP) and tri(p-tolyl) butylphosphonium iodide(TPTBP).The effects of the nature of associate counterions, the plastieizers and their concentrations in the membrane phase have been studied. The electrode based on theophylline-HTOA membrane has a sub-Nernstian response range from 2.0×10~2—6.3×10~(-5)mol/L,with an average slope of 48.0mV/pC. The limit of detection is 8.7×10~(-6)mol/L. The electrode responses were not affected by pH in the range 10-12. The potentiometric selectivity coefficients of various common inorganic and organic ions including those which are similar to theophylline in structure were determined. The Na_2CO_3-Na_2B_4O_7 buffer of pH 11 is selected as the background solution for potentiometric measurements. The electrode was used for determining the theophylline in pharmaceutical preparations with satisfactory results.
