A high-performance capillary electrophoresis with amperometric detection(CE-AD) method has been developed for the analysis of seven bioactive ingredients,namely ferulic acid(FA),vanillin,vanillic acid,p-hydroxybenzoic...A high-performance capillary electrophoresis with amperometric detection(CE-AD) method has been developed for the analysis of seven bioactive ingredients,namely ferulic acid(FA),vanillin,vanillic acid,p-hydroxybenzoic acid,caffeic acid,gallic acid and protocatechuic acid,in Rhizoma Chuanxiong.The effects of several factors such as the acidity and concentration of running buffer,the separation voltage,the applied potential to working electrode and the injection time were investigated.Under the optimum condit...展开更多
A new method of determination for roxithromycin tablets by non-aqueous capillary electrophoresis (NACE) with square-wave amperometric detection was carried out. Several parameters affecting the NACE-AD determination ...A new method of determination for roxithromycin tablets by non-aqueous capillary electrophoresis (NACE) with square-wave amperometric detection was carried out. Several parameters affecting the NACE-AD determination were studied. The data was modified by spline wavelet least square (SWLS). The method is simple, rapid and highly reliable for routine analysis.展开更多
An electrophoretic method was developed for the determination of several important catecholamine markers, namely norepinephrine, epinephrine, dopamine, metanephrine, vanillylmandelic acid and homovanillic acid in urin...An electrophoretic method was developed for the determination of several important catecholamine markers, namely norepinephrine, epinephrine, dopamine, metanephrine, vanillylmandelic acid and homovanillic acid in urine samples. Under the optimum conditions, the six marker compounds could be well separated with the major coexisting interference compound uric acid within 24 rain at a separation voltage of 16 kV in a borate running buffer (80 mmol/L, pH=9.48). Highly linear response can be obtained over three orders of magnitude for the above markers with the low limits of detection ranging from 1.0 ng/mL to 5.0 ng/mL(S/N=3). The proposed capillary electrophoresis with amperometric detection(CE-AD) method has been used to simultaneously determine the six catecholamine markers in urine samples of healthy volunteers and patients suffering from different diseases avoiding redundant measurements and high assay cost; and the electrochemical profiles can suggest more diagnostic information of multiple diseases, which provides a promising and convenient entry into primary diagnoses of several clinical diseases.展开更多
The present paper covers a simple, reliable and reproducible method, based on capillary zone electrophoresis(CZE) with amperometric detection(AD), for the separation and the determination of ephedrine hydrochloride, p...The present paper covers a simple, reliable and reproducible method, based on capillary zone electrophoresis(CZE) with amperometric detection(AD), for the separation and the determination of ephedrine hydrochloride, promethazine hydrochloride and codeine phosphate. Under the optimal conditions, the three analytes were base-line separated completely within 16 min. Good linear relationships between the peak heights and the concentrations of the three analytes were obtained with the correlation coefficients better than 0 9993. The method was directly applied to the determination of the active ingredients in pharmaceutical preparations and the assay results were satisfactory.展开更多
The fast separation capability of a novel miniaturized capillary electrophoresis with an amperometric detection (μCE-AD) system was demonstrated by determining clenbuterol and salbutamol in real samples. The effect...The fast separation capability of a novel miniaturized capillary electrophoresis with an amperometric detection (μCE-AD) system was demonstrated by determining clenbuterol and salbutamol in real samples. The effects of several factors such as the acidity and concentration of the running buffer, the separation voltage, the applied potential and the injection time on CE-AD were examined and optimized. Under the optimum conditions, the two β-agonists could be baseline separated within 60 s at a separation voltage of 2 kV in a 90 mmol/L H3BO3-Na2B4O7 running buffer (pH 7.4), which was not interfered by ascorbic acid and uric acid. Highly linear response was obtained for above compounds over three orders of magnitude with detection limits ranging from 1.20×10^-7 to 6.50×10^-8 mol/L (S/N=3). This method was successfully used in the analysis of feed and meat products with relatively simple extraction procedures.展开更多
Capillary electrophoresis (CE)/electrochemical detection (EC) for the simultaneous determination of hydrazine and isoniazid has been developed. The electrochemical method uses a novel modified electrode dispersed with...Capillary electrophoresis (CE)/electrochemical detection (EC) for the simultaneous determination of hydrazine and isoniazid has been developed. The electrochemical method uses a novel modified electrode dispersed with ultrafine platinum particles on the surface of a 30 mu m carbon fiber microelectrode. The unique characteristic of the Pt-particles modified carbon fiber microelectrode is its excellent stability. The current measurement for hydrazine is more sensitive than that of isoniazid. Selective determination of trace amount of free hydrazine in isoniazid and its formulation can be achieved at applied potential of 0.5 V.展开更多
Copper microelectrodes were used in microvoltammetry to detect histamine and several amino acid neurotransmitters. High sensitivity was obtained through the use of copper microelectrodes, and detection limits of 50 n...Copper microelectrodes were used in microvoltammetry to detect histamine and several amino acid neurotransmitters. High sensitivity was obtained through the use of copper microelectrodes, and detection limits of 50 nmol/L and 90 nmol/L were obtained for histamine and histidine, respectively. Furthermore, histamine and several amino acids neurotransmitters were firstly separated and detected by capillary electrophoresis with amperometric detection on copper microelectrodes. Mass limits of 490 amol and 440 amol were achieved for histamine and histidine, respectively, by using this mothod.展开更多
A novel method for fast determination of ethylendiamine (EDA) in Aminophylline Tablets has been developed by small-sized capillary electrophoresis with amperometric detection (small-CE-AD) coupled with field-ampli...A novel method for fast determination of ethylendiamine (EDA) in Aminophylline Tablets has been developed by small-sized capillary electrophoresis with amperometric detection (small-CE-AD) coupled with field-amplified sample injection (FASI). Under the optimum conditions, EDA and four aliphatic diamine homologs (1,3-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane and 1,6-diaminohexane) could be well separated within 6 min at a separation voltage of 2.0 kV in an acetate buffer solution of pH 3.8 with low limit of detection (LOD) of 1.3 × 10^-11 g/mL for EDA (S/N=3). The proposed method has been successfully applied to direct deter- mination of EDA content in different batches of Aminophylline Tablets. The method does not require off-line preconcentration and derivatization steps, which should find wide application fields including pharmaceuticals as an alternative to conventional and microchip CE approaches.展开更多
High performance capillary electrophoresis (HPCE) is a powerful tool for separation of complex compounds. Capillary electrophoresis with amperometric detection is a prospective research area in HPCE and has attracted ...High performance capillary electrophoresis (HPCE) is a powerful tool for separation of complex compounds. Capillary electrophoresis with amperometric detection is a prospective research area in HPCE and has attracted wide attention because of its high sensitivity, small dead volume and inexpensive equipment. Only a few reports on the use of chemically modified electrode (CME) in capillary electrophoresis have been published. In this note a novel modified electrode dispersed with ultrafine platinum particles on the surface of a 30 7μm carbon fibre microelectrode展开更多
Due to their important biological role as markers for different pathologies, sialic acid (SA) analyses are important for clinical research. In this work, a miniaturized capillary electrophoresis with amperometrie de...Due to their important biological role as markers for different pathologies, sialic acid (SA) analyses are important for clinical research. In this work, a miniaturized capillary electrophoresis with amperometrie detection (mini-CE-AD) was developed for the determination of N-aeetylneuraminic acid (NANA), which is the most widespread form of SAs. NANA was first oxidized by periodic acid in an acidic solution, and then the oxidation product β-formyl pyruvic acid was derivatized with electroactive 2-thiobarbituric acid (TBA) to form an electroactive NANA-TBA adduct, which could be readily determined by mini-CE-AD. The limit of detection (LOD) of NANA-TBA could achieve 0.50 μg/mL (1.6 μmol·L-1, S/N=3) based on an online enrichment approach of moving chemical reaction boundary. The proposed method was successfully applied to the analysis of NANA in human saliva, and the recoveries were in the range of 91.8%-109% with RSDs of 1.8%-3.9%. Due to its simple design and construction, low cost and portability, the mini-CE-AD device will possess more practicability in more field work as an alternative to conventional and microchip CE approaches.展开更多
A simple, reliable and reproducible method, based on capillary zone electrophoresis with amperometric detection (CZE-AD), has been developed for simultaneous determination of four active ingredients in Vc Yinqiao ta...A simple, reliable and reproducible method, based on capillary zone electrophoresis with amperometric detection (CZE-AD), has been developed for simultaneous determination of four active ingredients in Vc Yinqiao tablets including paracetamol, vitamin C, caffeic acid and chlorogenic acid. A carbon-disk electrode was used as working electrode and 0.95 V (versus SCE) was selected as detection potential. The optimal conditions of CZE experiment were 30 mmol·L^-1 borate solution (pH 9.5) as running buffer, 14 kV as separation voltage and 8 s (14 kV) as electro-kinetic sampling time. Under the selected optimum conditions, paracetamol, vitamin C, caffeic acid and chlorogenic acid could be perfectly separated within 22 min, and their detection limits (S/N=3) ranged from 5×10^-7 to 1 ×10^-6 mol·L^-1. This proposed method demonstrated good reproducibility with relative standard deviations of less than 3% for both migration time and peak current (n=7). The utility of this method was demonstrated by monitoring a kind of compound medicine named Vc Yinqiao tablets and the assay results were satisfactory.展开更多
On-column sample stacking technique has been used extensively in capillary zone electrophoresis (CZE) to enhance the sensitivity of the measurements with UV-Vis detection. However, the detection limits for CZE-separat...On-column sample stacking technique has been used extensively in capillary zone electrophoresis (CZE) to enhance the sensitivity of the measurements with UV-Vis detection. However, the detection limits for CZE-separation are still limit- ed due to the poor sensitivity of a UV-Vis detector. We incorporated field-amplified sample stacking technique into CZE with amperometric detection. Compared with the conventional electromigration injection , a negative peak of water was observed and a great enhancement of signals was obtained. The results in phosphate buffer with sodium dodecyl sulfate (SDS ) and 2-N-(morpholino) ethane sulphonic acid ( MES ) buffer were compared. Subnanomolar concentration limits for cate- cholamine neurotransmitters (dopamine, norepinephrine , epinephriine) and isopro- terenol were achieved in the 25 um capillary with two or three orders of magnitude lower than those with amperometric detection reported previously.展开更多
The composition of laminarin was firstly determined by analyzing its hydrolysis monosaccharides with capillary zone electrophoresis-amperometric detection (CZE-AD). Under the selected optimum conditions, fucose, galac...The composition of laminarin was firstly determined by analyzing its hydrolysis monosaccharides with capillary zone electrophoresis-amperometric detection (CZE-AD). Under the selected optimum conditions, fucose, galactose, glucose, mannose and xylose, which are hydrolysis products of laminarin, could be perfectly separated within 20 min and showed significant current responses at copper electrodes. The linear ranges of fucose, galactose and glucose were from 1.0×10 -6 to 2.0×10 -4 mol·L -1, those of mannose and xylose were from 5.0×10 -6 to 2.0×10 -4 mol·L -1, and their detection limits were at 10 -7 mol·L -1 level (S/N=3). The molar ratio of fucose, galactose, glucose, mannose and xylose in laminarin was 10.5∶2.8∶1.0∶7.3∶3.4 and the purity of this polysaccharide leached by the introduced leaching method was 95.7%. Compared to usual UV-vis and other spectrometric methods, analyzing polysaccharide by this method has some merits of quickness, low-volume sampling, simple instrumentation, high sensitivity and high reproducibility.展开更多
基金the financial support provided by the National Science Foundation of China(No. 20875032)the Basic Research Fund of the Science and Technology Commission of Shanghai Municipality(No. 09ZR1409700)
文摘A high-performance capillary electrophoresis with amperometric detection(CE-AD) method has been developed for the analysis of seven bioactive ingredients,namely ferulic acid(FA),vanillin,vanillic acid,p-hydroxybenzoic acid,caffeic acid,gallic acid and protocatechuic acid,in Rhizoma Chuanxiong.The effects of several factors such as the acidity and concentration of running buffer,the separation voltage,the applied potential to working electrode and the injection time were investigated.Under the optimum condit...
基金This work was supported by the National Natural Science Foundation of China and Guang Dong Provincial Natural Science Foundation(29675033 and 20175037 001237)
文摘A new method of determination for roxithromycin tablets by non-aqueous capillary electrophoresis (NACE) with square-wave amperometric detection was carried out. Several parameters affecting the NACE-AD determination were studied. The data was modified by spline wavelet least square (SWLS). The method is simple, rapid and highly reliable for routine analysis.
基金Supported by the National Natural Science Foundation of China(No.21205042) and the Special l~unds t0r the Development of Major Scientific Instruments and Equipment, China(No.2011YQ 15007205).
文摘An electrophoretic method was developed for the determination of several important catecholamine markers, namely norepinephrine, epinephrine, dopamine, metanephrine, vanillylmandelic acid and homovanillic acid in urine samples. Under the optimum conditions, the six marker compounds could be well separated with the major coexisting interference compound uric acid within 24 rain at a separation voltage of 16 kV in a borate running buffer (80 mmol/L, pH=9.48). Highly linear response can be obtained over three orders of magnitude for the above markers with the low limits of detection ranging from 1.0 ng/mL to 5.0 ng/mL(S/N=3). The proposed capillary electrophoresis with amperometric detection(CE-AD) method has been used to simultaneously determine the six catecholamine markers in urine samples of healthy volunteers and patients suffering from different diseases avoiding redundant measurements and high assay cost; and the electrochemical profiles can suggest more diagnostic information of multiple diseases, which provides a promising and convenient entry into primary diagnoses of several clinical diseases.
基金Supported by the Key L aboratory of Electroanalytical Chemistry,Changchun Institute of Applied Chem istry of Chi-nese AcademyofSciences
文摘The present paper covers a simple, reliable and reproducible method, based on capillary zone electrophoresis(CZE) with amperometric detection(AD), for the separation and the determination of ephedrine hydrochloride, promethazine hydrochloride and codeine phosphate. Under the optimal conditions, the three analytes were base-line separated completely within 16 min. Good linear relationships between the peak heights and the concentrations of the three analytes were obtained with the correlation coefficients better than 0 9993. The method was directly applied to the determination of the active ingredients in pharmaceutical preparations and the assay results were satisfactory.
文摘The fast separation capability of a novel miniaturized capillary electrophoresis with an amperometric detection (μCE-AD) system was demonstrated by determining clenbuterol and salbutamol in real samples. The effects of several factors such as the acidity and concentration of the running buffer, the separation voltage, the applied potential and the injection time on CE-AD were examined and optimized. Under the optimum conditions, the two β-agonists could be baseline separated within 60 s at a separation voltage of 2 kV in a 90 mmol/L H3BO3-Na2B4O7 running buffer (pH 7.4), which was not interfered by ascorbic acid and uric acid. Highly linear response was obtained for above compounds over three orders of magnitude with detection limits ranging from 1.20×10^-7 to 6.50×10^-8 mol/L (S/N=3). This method was successfully used in the analysis of feed and meat products with relatively simple extraction procedures.
基金Project supported by the National Natural Science Foundation of China.
文摘Capillary electrophoresis (CE)/electrochemical detection (EC) for the simultaneous determination of hydrazine and isoniazid has been developed. The electrochemical method uses a novel modified electrode dispersed with ultrafine platinum particles on the surface of a 30 mu m carbon fiber microelectrode. The unique characteristic of the Pt-particles modified carbon fiber microelectrode is its excellent stability. The current measurement for hydrazine is more sensitive than that of isoniazid. Selective determination of trace amount of free hydrazine in isoniazid and its formulation can be achieved at applied potential of 0.5 V.
文摘Copper microelectrodes were used in microvoltammetry to detect histamine and several amino acid neurotransmitters. High sensitivity was obtained through the use of copper microelectrodes, and detection limits of 50 nmol/L and 90 nmol/L were obtained for histamine and histidine, respectively. Furthermore, histamine and several amino acids neurotransmitters were firstly separated and detected by capillary electrophoresis with amperometric detection on copper microelectrodes. Mass limits of 490 amol and 440 amol were achieved for histamine and histidine, respectively, by using this mothod.
基金This work was financially supported by the National Natural Science Foundation of China (No. 21205042), the Special Funds for the Development of Major Scien- tific Instruments and Equipment (No. 2011YQ15007205), and the Fundamental Research Funds for the Central Universities.
文摘A novel method for fast determination of ethylendiamine (EDA) in Aminophylline Tablets has been developed by small-sized capillary electrophoresis with amperometric detection (small-CE-AD) coupled with field-amplified sample injection (FASI). Under the optimum conditions, EDA and four aliphatic diamine homologs (1,3-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane and 1,6-diaminohexane) could be well separated within 6 min at a separation voltage of 2.0 kV in an acetate buffer solution of pH 3.8 with low limit of detection (LOD) of 1.3 × 10^-11 g/mL for EDA (S/N=3). The proposed method has been successfully applied to direct deter- mination of EDA content in different batches of Aminophylline Tablets. The method does not require off-line preconcentration and derivatization steps, which should find wide application fields including pharmaceuticals as an alternative to conventional and microchip CE approaches.
基金Project supported by the National Natural Science Foundation of China.
文摘High performance capillary electrophoresis (HPCE) is a powerful tool for separation of complex compounds. Capillary electrophoresis with amperometric detection is a prospective research area in HPCE and has attracted wide attention because of its high sensitivity, small dead volume and inexpensive equipment. Only a few reports on the use of chemically modified electrode (CME) in capillary electrophoresis have been published. In this note a novel modified electrode dispersed with ultrafine platinum particles on the surface of a 30 7μm carbon fibre microelectrode
基金This work was supported by the National Natural Science Foundation of China (No. 21205042), the Daxia Foundation of East China Normal University (No. 2015DX-284) and the Students Innovative Experimental Project of Shanghai Municipality (No. 201610269070). The authors have declared no conflicts of interest.
文摘Due to their important biological role as markers for different pathologies, sialic acid (SA) analyses are important for clinical research. In this work, a miniaturized capillary electrophoresis with amperometrie detection (mini-CE-AD) was developed for the determination of N-aeetylneuraminic acid (NANA), which is the most widespread form of SAs. NANA was first oxidized by periodic acid in an acidic solution, and then the oxidation product β-formyl pyruvic acid was derivatized with electroactive 2-thiobarbituric acid (TBA) to form an electroactive NANA-TBA adduct, which could be readily determined by mini-CE-AD. The limit of detection (LOD) of NANA-TBA could achieve 0.50 μg/mL (1.6 μmol·L-1, S/N=3) based on an online enrichment approach of moving chemical reaction boundary. The proposed method was successfully applied to the analysis of NANA in human saliva, and the recoveries were in the range of 91.8%-109% with RSDs of 1.8%-3.9%. Due to its simple design and construction, low cost and portability, the mini-CE-AD device will possess more practicability in more field work as an alternative to conventional and microchip CE approaches.
文摘A simple, reliable and reproducible method, based on capillary zone electrophoresis with amperometric detection (CZE-AD), has been developed for simultaneous determination of four active ingredients in Vc Yinqiao tablets including paracetamol, vitamin C, caffeic acid and chlorogenic acid. A carbon-disk electrode was used as working electrode and 0.95 V (versus SCE) was selected as detection potential. The optimal conditions of CZE experiment were 30 mmol·L^-1 borate solution (pH 9.5) as running buffer, 14 kV as separation voltage and 8 s (14 kV) as electro-kinetic sampling time. Under the selected optimum conditions, paracetamol, vitamin C, caffeic acid and chlorogenic acid could be perfectly separated within 22 min, and their detection limits (S/N=3) ranged from 5×10^-7 to 1 ×10^-6 mol·L^-1. This proposed method demonstrated good reproducibility with relative standard deviations of less than 3% for both migration time and peak current (n=7). The utility of this method was demonstrated by monitoring a kind of compound medicine named Vc Yinqiao tablets and the assay results were satisfactory.
文摘On-column sample stacking technique has been used extensively in capillary zone electrophoresis (CZE) to enhance the sensitivity of the measurements with UV-Vis detection. However, the detection limits for CZE-separation are still limit- ed due to the poor sensitivity of a UV-Vis detector. We incorporated field-amplified sample stacking technique into CZE with amperometric detection. Compared with the conventional electromigration injection , a negative peak of water was observed and a great enhancement of signals was obtained. The results in phosphate buffer with sodium dodecyl sulfate (SDS ) and 2-N-(morpholino) ethane sulphonic acid ( MES ) buffer were compared. Subnanomolar concentration limits for cate- cholamine neurotransmitters (dopamine, norepinephrine , epinephriine) and isopro- terenol were achieved in the 25 um capillary with two or three orders of magnitude lower than those with amperometric detection reported previously.
文摘The composition of laminarin was firstly determined by analyzing its hydrolysis monosaccharides with capillary zone electrophoresis-amperometric detection (CZE-AD). Under the selected optimum conditions, fucose, galactose, glucose, mannose and xylose, which are hydrolysis products of laminarin, could be perfectly separated within 20 min and showed significant current responses at copper electrodes. The linear ranges of fucose, galactose and glucose were from 1.0×10 -6 to 2.0×10 -4 mol·L -1, those of mannose and xylose were from 5.0×10 -6 to 2.0×10 -4 mol·L -1, and their detection limits were at 10 -7 mol·L -1 level (S/N=3). The molar ratio of fucose, galactose, glucose, mannose and xylose in laminarin was 10.5∶2.8∶1.0∶7.3∶3.4 and the purity of this polysaccharide leached by the introduced leaching method was 95.7%. Compared to usual UV-vis and other spectrometric methods, analyzing polysaccharide by this method has some merits of quickness, low-volume sampling, simple instrumentation, high sensitivity and high reproducibility.