The paper reported a analytical method for determining the trace iodine in environmental and biological materials.After mixed with the ashing aids KOH/KClO 3 and dried thoroughly,the samples were ashed in muffle furna...The paper reported a analytical method for determining the trace iodine in environmental and biological materials.After mixed with the ashing aids KOH/KClO 3 and dried thoroughly,the samples were ashed in muffle furnace at 600℃.Then the residues were dissolved with water.By means of mixed oxidants KMnO 4/NaOCl,iodide was transformed into iodate and excessive oxidants were reduced with the solution of sodium sulfite.In medium of 0 2 mol/L KNO 3-0 1 mol/L KCl iodate was determined with osillopolarography.The peak potential lay at -1 25V(vs.SCE).The concentration of iodide related to the secondary differential of the peak currents ranged from 0 001 to 10mg/L with a good linear relation.The polarographical behaviors of iodate were studied.The method had been applied to determine trace iodine in well,salt,urine,human hair and maize with satisfactory results.展开更多
研究重要中间体芳杂环甲酰胺类化合物合成的新方法。用溴代芳杂环类化合物与甲酰胺为原料,以便宜易得的氧化铜为催化剂,在缚酸剂的存在的情况下进行反应合成目标化合物。并探讨反应时间、反应温度、加入原料的物质的量比[n(溴代芳杂环...研究重要中间体芳杂环甲酰胺类化合物合成的新方法。用溴代芳杂环类化合物与甲酰胺为原料,以便宜易得的氧化铜为催化剂,在缚酸剂的存在的情况下进行反应合成目标化合物。并探讨反应时间、反应温度、加入原料的物质的量比[n(溴代芳杂环类化合物)︰n(甲酰胺)]等因素对目标化合物产率的影响。最后以最优化条件得到芳杂环酰胺类化合物,最佳条件为:n(溴代芳杂环)︰n(甲酰胺)=1︰25,反应时间为8h,反应温度为120℃。并合成一系列有代表性的芳杂环酰胺类化合物,其结构经1 H NMR和13 C NMR确证。该路线工艺流程简单、快速,三废少且易处理,适合工业化生产。展开更多
The authors had reported the determination of ephedrine by osillopolarography.In acetate buffer（pH 4.0） ephedrine reacted with nitrite to form N-nitrosoephedrine.The reaction needed only 2 minutes with a boiling wat...The authors had reported the determination of ephedrine by osillopolarography.In acetate buffer（pH 4.0） ephedrine reacted with nitrite to form N-nitrosoephedrine.The reaction needed only 2 minutes with a boiling water bath.After removing excessive nitrite,N-nitrosoephedrine gave a well polarographic reductive wave at -0.82V（vs.SCE） in acidic medium.The linear relationship between the concentrations of ephedrine and the peak currents of the osillopolarographic wave was proportional in the range of 0.10～200×10-6 （g/mL.）The method was sensitive,rapid and simple.It had been applied to determine ephedrine in pharmaceuticals with satisfactory results.展开更多
文摘The paper reported a analytical method for determining the trace iodine in environmental and biological materials.After mixed with the ashing aids KOH/KClO 3 and dried thoroughly,the samples were ashed in muffle furnace at 600℃.Then the residues were dissolved with water.By means of mixed oxidants KMnO 4/NaOCl,iodide was transformed into iodate and excessive oxidants were reduced with the solution of sodium sulfite.In medium of 0 2 mol/L KNO 3-0 1 mol/L KCl iodate was determined with osillopolarography.The peak potential lay at -1 25V(vs.SCE).The concentration of iodide related to the secondary differential of the peak currents ranged from 0 001 to 10mg/L with a good linear relation.The polarographical behaviors of iodate were studied.The method had been applied to determine trace iodine in well,salt,urine,human hair and maize with satisfactory results.
文摘研究重要中间体芳杂环甲酰胺类化合物合成的新方法。用溴代芳杂环类化合物与甲酰胺为原料,以便宜易得的氧化铜为催化剂,在缚酸剂的存在的情况下进行反应合成目标化合物。并探讨反应时间、反应温度、加入原料的物质的量比[n(溴代芳杂环类化合物)︰n(甲酰胺)]等因素对目标化合物产率的影响。最后以最优化条件得到芳杂环酰胺类化合物,最佳条件为:n(溴代芳杂环)︰n(甲酰胺)=1︰25,反应时间为8h,反应温度为120℃。并合成一系列有代表性的芳杂环酰胺类化合物,其结构经1 H NMR和13 C NMR确证。该路线工艺流程简单、快速,三废少且易处理,适合工业化生产。
文摘The authors had reported the determination of ephedrine by osillopolarography.In acetate buffer（pH 4.0） ephedrine reacted with nitrite to form N-nitrosoephedrine.The reaction needed only 2 minutes with a boiling water bath.After removing excessive nitrite,N-nitrosoephedrine gave a well polarographic reductive wave at -0.82V（vs.SCE） in acidic medium.The linear relationship between the concentrations of ephedrine and the peak currents of the osillopolarographic wave was proportional in the range of 0.10～200×10-6 （g/mL.）The method was sensitive,rapid and simple.It had been applied to determine ephedrine in pharmaceuticals with satisfactory results.
