Myoglobin was immobilized on edge-plane pyrolytic graphite（EPG）electrodes by sodium alginate hydrogel.The protein entrapped in the sodium alginate film undergoes fast direct electron-transfer reactions with the form...Myoglobin was immobilized on edge-plane pyrolytic graphite（EPG）electrodes by sodium alginate hydrogel.The protein entrapped in the sodium alginate film undergoes fast direct electron-transfer reactions with the formal potential(Eo′)of-0.296V（vs SCE）,corresponding to FeⅢ+e-→FeⅡ,The Eo′s are linearly dependent on solution pH with the slope value of-35.0 mV/pH,indicating that the electron transfer was proton-coupled.The mechanisms for catalytic reduction of oxygen,hydrogen peroxide and nitric oxide by myoglobin entrapped in sodium alginate hydrogel were also explored.展开更多
A new method for the determination of trace nitrite by spectrophotometric after cloud point extraction was proposed.The effects of experimental conditions such as acidity,concentration of chromogenic reagent and surfa...A new method for the determination of trace nitrite by spectrophotometric after cloud point extraction was proposed.The effects of experimental conditions such as acidity,concentration of chromogenic reagent and surfactant,equilibration temperature and time on cloud point extraction were discussed.Under the optimum conditions,a good linear relationship was obtained in the range of 4.0～200 μg/L of the nitrite(r=0.9998),the detection limits of 0.43 μg/L.The recoveries fell in the range from 97.7% to 102.4% and the relative standard deviations were between 1.8% and 3.2%.This method has been applied for the determination of nitrite in real water samples with satisfactory results.展开更多
文摘Myoglobin was immobilized on edge-plane pyrolytic graphite（EPG）electrodes by sodium alginate hydrogel.The protein entrapped in the sodium alginate film undergoes fast direct electron-transfer reactions with the formal potential(Eo′)of-0.296V（vs SCE）,corresponding to FeⅢ+e-→FeⅡ,The Eo′s are linearly dependent on solution pH with the slope value of-35.0 mV/pH,indicating that the electron transfer was proton-coupled.The mechanisms for catalytic reduction of oxygen,hydrogen peroxide and nitric oxide by myoglobin entrapped in sodium alginate hydrogel were also explored.
文摘A new method for the determination of trace nitrite by spectrophotometric after cloud point extraction was proposed.The effects of experimental conditions such as acidity,concentration of chromogenic reagent and surfactant,equilibration temperature and time on cloud point extraction were discussed.Under the optimum conditions,a good linear relationship was obtained in the range of 4.0～200 μg/L of the nitrite(r=0.9998),the detection limits of 0.43 μg/L.The recoveries fell in the range from 97.7% to 102.4% and the relative standard deviations were between 1.8% and 3.2%.This method has been applied for the determination of nitrite in real water samples with satisfactory results.
