The feasibility of using electrodes modified with polyaniline incorporated carbon particles films for improving the precision of coulometric titration is demonstrated. The problem of large deviation produced during de...The feasibility of using electrodes modified with polyaniline incorporated carbon particles films for improving the precision of coulometric titration is demonstrated. The problem of large deviation produced during determining polyisoprene by coulometric titration with direct titration technique(double Pt electrodes indicating electrode) has been solved. In the titration process, polyisoprene alcohol, an electro-inactive species, is adsorbed on the surface of the bare Pt electrode, which inhibits the electrode reaction of Br - and Br 2. Therefore, when the titration reaches the end-point, the detected current will slowly change with time, which can make the repeatability of end-point poor. The atomic force microscopic images show the morphology of the electrode surface of adsorbing polyisoprene alcohol. The application of the chemically modified electrode instead of the bare Pt electrode to indicating the end-point has been investigated. The results show that the Pt electrode coated with polyaniline incorporated carbon particles films is an excellent indicator electrode. This electrode has advantages that the indicating signals are sharp and repeatable at end-point. The precision and the accuracy of the determination of polyisoprene alcohol are satisfactory.展开更多
A method for the determination of Mylis by coulometric titration was developed.The titration was carried out in a mixture of 1 mol/L KBr-2 mol/L HCl(1:1)and bromine was generated at the anode, Mylis reacted with one m...A method for the determination of Mylis by coulometric titration was developed.The titration was carried out in a mixture of 1 mol/L KBr-2 mol/L HCl(1:1)and bromine was generated at the anode, Mylis reacted with one mole of bromine with a n value of 2. The advantages of this method are simple and rapid,it can be used to analyze small amount of sample.展开更多
A systematic analytical method for the species of trace sulfur in water has been developed by using electrochemically coulometric titration in combination with several separation and concentration techniques.Based on ...A systematic analytical method for the species of trace sulfur in water has been developed by using electrochemically coulometric titration in combination with several separation and concentration techniques.Based on the reaction of iodine with sodium azide,the studies were carried out on the catalytically coulometric determination of ppb levels of ionic or molecular sulfides,thiosulfates and hydrogen sulfide in wateri constant current coulometric determination of sulfites;and indirect coulometric determination of sulfate salts and esters.Coupled with the determination of the content of total sulfur,the scope of distribution of the species of inorganic sulfur(including trace sulfur compounds in labile state)and organic sulfur in water was given.The method thus developed was found to be featured by being easy and reliable to operate with a higher sensitivity and reproducibility and to be applicable to the analysis of sulfur species in water.展开更多
基金Supported by the Science and Technology Comm ission of Henan Province and Education Com mission of HenanProvince
文摘The feasibility of using electrodes modified with polyaniline incorporated carbon particles films for improving the precision of coulometric titration is demonstrated. The problem of large deviation produced during determining polyisoprene by coulometric titration with direct titration technique(double Pt electrodes indicating electrode) has been solved. In the titration process, polyisoprene alcohol, an electro-inactive species, is adsorbed on the surface of the bare Pt electrode, which inhibits the electrode reaction of Br - and Br 2. Therefore, when the titration reaches the end-point, the detected current will slowly change with time, which can make the repeatability of end-point poor. The atomic force microscopic images show the morphology of the electrode surface of adsorbing polyisoprene alcohol. The application of the chemically modified electrode instead of the bare Pt electrode to indicating the end-point has been investigated. The results show that the Pt electrode coated with polyaniline incorporated carbon particles films is an excellent indicator electrode. This electrode has advantages that the indicating signals are sharp and repeatable at end-point. The precision and the accuracy of the determination of polyisoprene alcohol are satisfactory.
文摘A method for the determination of Mylis by coulometric titration was developed.The titration was carried out in a mixture of 1 mol/L KBr-2 mol/L HCl(1:1)and bromine was generated at the anode, Mylis reacted with one mole of bromine with a n value of 2. The advantages of this method are simple and rapid,it can be used to analyze small amount of sample.
文摘A systematic analytical method for the species of trace sulfur in water has been developed by using electrochemically coulometric titration in combination with several separation and concentration techniques.Based on the reaction of iodine with sodium azide,the studies were carried out on the catalytically coulometric determination of ppb levels of ionic or molecular sulfides,thiosulfates and hydrogen sulfide in wateri constant current coulometric determination of sulfites;and indirect coulometric determination of sulfate salts and esters.Coupled with the determination of the content of total sulfur,the scope of distribution of the species of inorganic sulfur(including trace sulfur compounds in labile state)and organic sulfur in water was given.The method thus developed was found to be featured by being easy and reliable to operate with a higher sensitivity and reproducibility and to be applicable to the analysis of sulfur species in water.
