A simple and sensitive spectroelectrochemistry method for the determination of vitamin K3 was developed by combining electrolysis and fluoremetry. This method was based on that vitamin K3 was reduced at a glassy carbo...A simple and sensitive spectroelectrochemistry method for the determination of vitamin K3 was developed by combining electrolysis and fluoremetry. This method was based on that vitamin K3 was reduced at a glassy carbon electrode, and its product with characteristic fluorescence at 420 nm was determined with excitation wavelength at 309 nm. Under optimized electrochemical reaction conditions and fluorescent experiment parameters, the fluorescence intensity was proportional to the concentration of vitamin K3 in a range from 3.50×10^-7 to 1.05×10^-5 mol/L with a correlation coefficient of 0.9991, and detection limit was estimated to be 7.50× 10^-8 mol/L at a signal/noise ra- tio of 3. The relative standard deviation was less than 4.3%（n=5） and the recovery was in a range of 97%-105% for the determination of vitamin K3 in pharmaceutical preparations. The result is satisfactory for the determination of vitamin K3 as comparison to that from HPLC method.展开更多
The adhesion mechanics of coal and the behavior of the coal adhesion to the hopper are analyzed. A model coal hopper is developed, and the model experiments are made by using the surface electro osmosis technology ac...The adhesion mechanics of coal and the behavior of the coal adhesion to the hopper are analyzed. A model coal hopper is developed, and the model experiments are made by using the surface electro osmosis technology according to the processing conditions. The parameters of the surface electro osmosis technology are optimized by the method of orthogonal polynomial regression designing. The result shows that the surface electro osmosis technique is one of the good methods to solve the adhering problem of coal to the coal hopper in transfer piping.展开更多
基金Supported by the National Nature Science Foundation of China(No.20635020)the Open-end Fund of State Key Labo-ratory of Fine Chemicals, China(No.KF0508)
文摘A simple and sensitive spectroelectrochemistry method for the determination of vitamin K3 was developed by combining electrolysis and fluoremetry. This method was based on that vitamin K3 was reduced at a glassy carbon electrode, and its product with characteristic fluorescence at 420 nm was determined with excitation wavelength at 309 nm. Under optimized electrochemical reaction conditions and fluorescent experiment parameters, the fluorescence intensity was proportional to the concentration of vitamin K3 in a range from 3.50×10^-7 to 1.05×10^-5 mol/L with a correlation coefficient of 0.9991, and detection limit was estimated to be 7.50× 10^-8 mol/L at a signal/noise ra- tio of 3. The relative standard deviation was less than 4.3%（n=5） and the recovery was in a range of 97%-105% for the determination of vitamin K3 in pharmaceutical preparations. The result is satisfactory for the determination of vitamin K3 as comparison to that from HPLC method.
文摘The adhesion mechanics of coal and the behavior of the coal adhesion to the hopper are analyzed. A model coal hopper is developed, and the model experiments are made by using the surface electro osmosis technology according to the processing conditions. The parameters of the surface electro osmosis technology are optimized by the method of orthogonal polynomial regression designing. The result shows that the surface electro osmosis technique is one of the good methods to solve the adhering problem of coal to the coal hopper in transfer piping.
