A new ion selective electrode for salicylate based on N,N＇-（aminoethyl）ethylenediamide bis（2-salicylideneimine） binuclear copper（Ⅱ） complex [Cu（Ⅱ）2-AEBS] as an ionophore was developed. The electrode has a l...A new ion selective electrode for salicylate based on N,N＇-（aminoethyl）ethylenediamide bis（2-salicylideneimine） binuclear copper（Ⅱ） complex [Cu（Ⅱ）2-AEBS] as an ionophore was developed. The electrode has a linear range from 1.0 × 10^-1 to 5.0 ×10^-7 mol·L^- 1 with a near-Nemstian slope of （ - 55 ±1 ） mV/decade and a detection limit of 2.0 × 10-7 mol·L^-1 in phosphorate buffer solution of pH 5.0 at 25 ℃. It shows good selectivity for Sal^- and displays anti-Hofmeister selectivity sequence： Sal^-〉SCN^-〉 ClO4^- 〉I^-〉 NO2^- 〉Br^-〉 NO3^- 〉Cl^-〉 SO3^2- 〉 SO4^2- The proposed sensor based on binuclear copper（Ⅱ）complex has a fast response time of 5-10 s and can be used for at least 2 months without any major deviation. The response mechanism is discussed in view of the alternating current （AC） impedance technique and the UV-vis spectroscopy technique. The effect of the electrode membrane compositions and the experimental conditions were studied. The electrode has been successfully used for the determination of salicylate ion in drug pharmaceutical preparations.展开更多
We investigated phytotoxicity in seven plant species exposed to a range of concentrations （0- 500 mg· kg^-1 soil） of di-n-butyl phthalate （DnBP） or his （2- ethylhexyl） phthalate （DEHP）, two representative...We investigated phytotoxicity in seven plant species exposed to a range of concentrations （0- 500 mg· kg^-1 soil） of di-n-butyl phthalate （DnBP） or his （2- ethylhexyl） phthalate （DEHP）, two representative phthalate esters （PAEs） nominated by USEPA as priority pollutants and known environmental estrogens. We studied seed germination, root elongation, seedling growth, biomass （fresh weight, FW） and malondialdehyde （MDA） content of shoots and roots of wheat （Triticum aestivum L.）, alfalfa （Medicago sativa L.）, perennial ryegrass （Lolium perenne）, radish （Raphanus sativus L.）, cucumber （Cucumis sativus L.）, oat （Avena sativa） and onion （Allium cepa L.）, together with monitoring of plant pigment content （chlorophyll a, b and earotinoids） in alfalfa, radish and onion shoots. Root elongation, seedling growth and biomass of the test species were generally inhibited by DnBP but not by DEHP, indicating a lower level of phytotoxicity of DEHP than of DnBP. MDA contents of four species were promoted by PAE exposure, but not in alfalfa, ryegrass or onion shoots, indicating lower sensitivity of these three species to PAE pollutants. Plant pigment contents were clearly affected under the stress of both pollutants, implying the potential damage to the photosynthetic system of test plants, mainly by decreasing the content of chlorophyll a and b. Results of DnBP and DEHP phytotoxicity to the primary growth of test plants has provided information for the assessment of their environmental risk in the soil and also forms a basis for the further analysis of their toxic effects over the whole growth period of different plant species.展开更多
基金Project supported by the National Natural Science Foundation of China （No. 29705001） and the Natural Science Foundation of Chongqing City （Nos. CSTC-2004BB4149 and CSTC-2005BB4100）.
文摘A new ion selective electrode for salicylate based on N,N＇-（aminoethyl）ethylenediamide bis（2-salicylideneimine） binuclear copper（Ⅱ） complex [Cu（Ⅱ）2-AEBS] as an ionophore was developed. The electrode has a linear range from 1.0 × 10^-1 to 5.0 ×10^-7 mol·L^- 1 with a near-Nemstian slope of （ - 55 ±1 ） mV/decade and a detection limit of 2.0 × 10-7 mol·L^-1 in phosphorate buffer solution of pH 5.0 at 25 ℃. It shows good selectivity for Sal^- and displays anti-Hofmeister selectivity sequence： Sal^-〉SCN^-〉 ClO4^- 〉I^-〉 NO2^- 〉Br^-〉 NO3^- 〉Cl^-〉 SO3^2- 〉 SO4^2- The proposed sensor based on binuclear copper（Ⅱ）complex has a fast response time of 5-10 s and can be used for at least 2 months without any major deviation. The response mechanism is discussed in view of the alternating current （AC） impedance technique and the UV-vis spectroscopy technique. The effect of the electrode membrane compositions and the experimental conditions were studied. The electrode has been successfully used for the determination of salicylate ion in drug pharmaceutical preparations.
文摘We investigated phytotoxicity in seven plant species exposed to a range of concentrations （0- 500 mg· kg^-1 soil） of di-n-butyl phthalate （DnBP） or his （2- ethylhexyl） phthalate （DEHP）, two representative phthalate esters （PAEs） nominated by USEPA as priority pollutants and known environmental estrogens. We studied seed germination, root elongation, seedling growth, biomass （fresh weight, FW） and malondialdehyde （MDA） content of shoots and roots of wheat （Triticum aestivum L.）, alfalfa （Medicago sativa L.）, perennial ryegrass （Lolium perenne）, radish （Raphanus sativus L.）, cucumber （Cucumis sativus L.）, oat （Avena sativa） and onion （Allium cepa L.）, together with monitoring of plant pigment content （chlorophyll a, b and earotinoids） in alfalfa, radish and onion shoots. Root elongation, seedling growth and biomass of the test species were generally inhibited by DnBP but not by DEHP, indicating a lower level of phytotoxicity of DEHP than of DnBP. MDA contents of four species were promoted by PAE exposure, but not in alfalfa, ryegrass or onion shoots, indicating lower sensitivity of these three species to PAE pollutants. Plant pigment contents were clearly affected under the stress of both pollutants, implying the potential damage to the photosynthetic system of test plants, mainly by decreasing the content of chlorophyll a and b. Results of DnBP and DEHP phytotoxicity to the primary growth of test plants has provided information for the assessment of their environmental risk in the soil and also forms a basis for the further analysis of their toxic effects over the whole growth period of different plant species.
