A new method for the determination of arecoline in Semen Arecae decoction pieces by microchip capillary electrophoresis with contactless conductivity detection （MCE-CCD） was proposed. The effects of various electrop...A new method for the determination of arecoline in Semen Arecae decoction pieces by microchip capillary electrophoresis with contactless conductivity detection （MCE-CCD） was proposed. The effects of various electrophoretic operating parameters on the analysis of arecoline were studied. Under the optimal conditions, arecoline was rapidly separated and detected in 1 rain with good linearity over the concentration range of 20 1500 uM （r2=0.9991） and the detection limit of 5 uM （S/N=3）. The method was used for the analysis of arecoline satisfactorily with a recovery of 96.8 -104%.展开更多
Microchip capillary electrophoresis （MCE） has significant impact on diagnostic testing. One of the most importance in clinical analysis test is the determination of cholesterol level in blood, because its increase i...Microchip capillary electrophoresis （MCE） has significant impact on diagnostic testing. One of the most importance in clinical analysis test is the determination of cholesterol level in blood, because its increase is associated with coronary heart disease which is a major cause of death world over. Polydimethylsiloxane （PDMS） was material used to make a MCE for determination of cholesterol. Hydrogen peroxide was generated from the oxidation of cholesterol with cholesterol oxidase （ChOx） and was detected electrochemically at a downstream gold （Au） wire electrode by amperometry. Various parameters, such as the detection potential, concentration of running buffer, pH of running buffer, separation voltage, injection time, and concentration of ChOx, were studied. The migration time of cholesterol is less than 100s and the calibration curve is linear from 50 mg.dL-1 to 250 mg-dL-1 with the coefficient of determination （R2） of 0.9955. Therefore, this proposed assay is very rapid and sensitive for the detection of cholesterol.展开更多
A micellar capillary electrophoresis（MCE） method based on on-line sweeping technique was（developed） for a determination of trace quinolones,ciprofloxacin ofloxacin and enrofloxacin in pork tissue.The pork tissue s...A micellar capillary electrophoresis（MCE） method based on on-line sweeping technique was（developed） for a determination of trace quinolones,ciprofloxacin ofloxacin and enrofloxacin in pork tissue.The pork tissue samples were deproteinized with trichloroacetic acid and in the running buffer of 20 mmol/L（Na2B4O7）+80 mmol/L sodium dodecyl sulfate（SDS）,pH=9.6,the ciprofloxacin,ofloxacin and enrofloxacin in the sample were successfully separated and detected within 200 s,in a non-coating fused-silica capillary column（48.5 cm×75 μm i.d.,effective length 40 cm） at separation voltage of 18 kV,and the injection pressure of 15×102 Pa,with UV detection at 278 nm.The detection limits of ciprofloxacin,ofloxacin and enrofloxacin were 0.007,0.016 and 0.020 mg/L,and RSD were 2.0%,2.4% and 2.6%,respectively.This method allows of up to 600-fold accumulation concentration of ciprofloxacin and can be used to separate and detect the residuals of trace medicines in animal food.展开更多
A poly(methyl methacrylate)-based capillary electrophoresis microchip, integrated with a microelectrode-based end-column amperometric detection, was described. A short unclosed portion of the separation channel from t...A poly(methyl methacrylate)-based capillary electrophoresis microchip, integrated with a microelectrode-based end-column amperometric detection, was described. A short unclosed portion of the separation channel from the detection cell was used as a working-electrode guide channel. With the aid of a three-dimension micropositioner and an optical microscope, a home-made 6 μm carbon-fiber microdisk electrode(tip diameter of 20 μm) was positioned along the guide channel at 30 μm distance from the channel outlet. With dopamine and catechol the as model analytes, the analytical performance of the system was demonstrated and the detection limit of 1.6×10 -7mol/L for dopamine was achieved, to our knowledge, which is the lowest value than that from published literatures using electrophoresis microchip with end-column amperometric detection.展开更多
基金support from the National Natural Science Foundation of China (Nos. 20727006,21075139)Guangdong Provincial Science and Technology Project (2008A030102009)the Medical Scientific Research Foundation of Guangdong Province(A2012155)
文摘A new method for the determination of arecoline in Semen Arecae decoction pieces by microchip capillary electrophoresis with contactless conductivity detection （MCE-CCD） was proposed. The effects of various electrophoretic operating parameters on the analysis of arecoline were studied. Under the optimal conditions, arecoline was rapidly separated and detected in 1 rain with good linearity over the concentration range of 20 1500 uM （r2=0.9991） and the detection limit of 5 uM （S/N=3）. The method was used for the analysis of arecoline satisfactorily with a recovery of 96.8 -104%.
基金supported by National Center of Excellence for Petroleum,Petrochemicals,and Advanced Materials,and the CU Graduate School Thesis Grant
文摘Microchip capillary electrophoresis （MCE） has significant impact on diagnostic testing. One of the most importance in clinical analysis test is the determination of cholesterol level in blood, because its increase is associated with coronary heart disease which is a major cause of death world over. Polydimethylsiloxane （PDMS） was material used to make a MCE for determination of cholesterol. Hydrogen peroxide was generated from the oxidation of cholesterol with cholesterol oxidase （ChOx） and was detected electrochemically at a downstream gold （Au） wire electrode by amperometry. Various parameters, such as the detection potential, concentration of running buffer, pH of running buffer, separation voltage, injection time, and concentration of ChOx, were studied. The migration time of cholesterol is less than 100s and the calibration curve is linear from 50 mg.dL-1 to 250 mg-dL-1 with the coefficient of determination （R2） of 0.9955. Therefore, this proposed assay is very rapid and sensitive for the detection of cholesterol.
文摘A micellar capillary electrophoresis（MCE） method based on on-line sweeping technique was（developed） for a determination of trace quinolones,ciprofloxacin ofloxacin and enrofloxacin in pork tissue.The pork tissue samples were deproteinized with trichloroacetic acid and in the running buffer of 20 mmol/L（Na2B4O7）+80 mmol/L sodium dodecyl sulfate（SDS）,pH=9.6,the ciprofloxacin,ofloxacin and enrofloxacin in the sample were successfully separated and detected within 200 s,in a non-coating fused-silica capillary column（48.5 cm×75 μm i.d.,effective length 40 cm） at separation voltage of 18 kV,and the injection pressure of 15×102 Pa,with UV detection at 278 nm.The detection limits of ciprofloxacin,ofloxacin and enrofloxacin were 0.007,0.016 and 0.020 mg/L,and RSD were 2.0%,2.4% and 2.6%,respectively.This method allows of up to 600-fold accumulation concentration of ciprofloxacin and can be used to separate and detect the residuals of trace medicines in animal food.
文摘A poly(methyl methacrylate)-based capillary electrophoresis microchip, integrated with a microelectrode-based end-column amperometric detection, was described. A short unclosed portion of the separation channel from the detection cell was used as a working-electrode guide channel. With the aid of a three-dimension micropositioner and an optical microscope, a home-made 6 μm carbon-fiber microdisk electrode(tip diameter of 20 μm) was positioned along the guide channel at 30 μm distance from the channel outlet. With dopamine and catechol the as model analytes, the analytical performance of the system was demonstrated and the detection limit of 1.6×10 -7mol/L for dopamine was achieved, to our knowledge, which is the lowest value than that from published literatures using electrophoresis microchip with end-column amperometric detection.
