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Xingguo Chen - One of the best experts on this subject based on the ideXlab platform.
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Micelle to solvent stacking of two alkaloids in Nonaqueous Capillary Electrophoresis.
Journal of chromatography. A, 2011Co-Authors: Hua-dong Zhu, Hongli Chen, Xingguo ChenAbstract:Abstract This paper for the first time describes the development of micelle to solvent stacking (MSS) to Nonaqueous Capillary Electrophoresis (NACE). In this proposed MSS-NACE, sodium dodecyl sulfate (SDS) micelles transport, release, and focus analytes from the sample solution to the running buffer using methanol as their solvent. After the focusing step, the focused analytes were separated via NACE. The focusing mechanism and influencing factors were discussed using berberine (BBR) and jatrorrhizine (JTZ) as model compounds. And the optimum condition was obtained as following: 50 mM ammonium acetate, 6% (v/v) acetic acid and 10 mM SDS in redistilled water as sample matrix, 50 mM ammonium acetate and 6% (v/v) acetic acid in pure methanol as the running buffer, −20 kV focusing voltage with 30 min focusing time. Under these conditions, this method afforded limits of detection (S/N = 3) of 0.002 μg/mL and 0.003 μg/mL for BBR and JTZ, respectively. In contrast to conventional NACE, the concentration sensitivity was improved 128–153-fold.
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separation and determination of pseudoephedrine dextromethorphan diphenhydramine and chlorpheniramine in cold medicines by Nonaqueous Capillary Electrophoresis
Journal of Pharmaceutical and Biomedical Analysis, 2005Co-Authors: Yuming Dong, Xingguo Chen, Xiaofeng Chen, Yonglei Chen, Zhide HuAbstract:Abstract An easy, rapid and simple Nonaqueous Capillary Electrophoresis (NACE) method was developed for the identification and determination of four basic nitrogenous compounds, i.e. pseudoephedrine (PE), dextromethorphan (DXM), diphenhydramine (DHM) and chlorpheniramine (CLP). The most suitable running buffer was composed of 40 mM ammonium acetate, 10% acetonitrile (ACN) in methanol with a fused-silica Capillary column (47 cm × 75 μm i.d.), 25 kV applied voltage and 25 °C Capillary temperature. The calibration curves revealed linear relationships between the peak area for each analyte and its concentration (correlation coefficients: 0.9993 for PE, 0.9971 for DXM, 0.9991 for DHM, and 0.9995 for CLP, respectively). The relative standard deviations of the migration time and peak area of the four compounds were 0.37, 3.90, 0.73 and 0.68, and 2.80, 3.50, 1.60 and 3.70%, respectively. The method was successfully applied to determine the four compounds in five cold medicines, the recoveries of the four constituents ranging between 91 and 109%.
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Novel and simple Nonaqueous Capillary Electrophoresis separation and determination bioactive triterpenes in Chinese herbs.
Journal of pharmaceutical and biomedical analysis, 2005Co-Authors: Lan Ding, Kan Tian, Xingguo ChenAbstract:Abstract Three bioactive triterpenes ursolic acid, oleanolic acid and 2α,3β,24-trihydroxy-urs-12-en-28-oic acid were simultaneously separated by Nonaqueous Capillary Electrophoresis (NACE) with methanol:acetonitrile (65:35 v/v) mixture containing 90 mm trishydroxymethylaminomethane (Tris) at an applied voltage of +25 kV and a hydrodynamic injection of 5 s. The effect of solvent composition, electrolyte nature and concentration on the electrophoretic behavior of the analytes were systematically studied. Separations were carried out in a fused-silica Capillary tube with UV detection at 214 nm. Good separation and correlation coefficients were obtained. Meanwhile, the method was applied to separation and determination the three components in six Chinese herbs extraction. It is concluded that this method could be used for speedy and accurate qualitative and quantitative analysis of bioactive triterpenes in Chinese herbs.
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Separation and determination of pseudoephedrine, dextromethorphan, diphenhydramine and chlorpheniramine in cold medicines by Nonaqueous Capillary Electrophoresis.
Journal of pharmaceutical and biomedical analysis, 2005Co-Authors: Yuming Dong, Xiaofeng Chen, Yonglei Chen, Xingguo ChenAbstract:An easy, rapid and simple Nonaqueous Capillary Electrophoresis (NACE) method was developed for the identification and determination of four basic nitrogenous compounds, i.e. pseudoephedrine (PE), dextromethorphan (DXM), diphenhydramine (DHM) and chlorpheniramine (CLP). The most suitable running buffer was composed of 40 mM ammonium acetate, 10% acetonitrile (ACN) in methanol with a fused-silica Capillary column (47 cm x 75 microm i.d.), 25 kV applied voltage and 25 degrees C Capillary temperature. The calibration curves revealed linear relationships between the peak area for each analyte and its concentration (correlation coefficients: 0.9993 for PE, 0.9971 for DXM, 0.9991 for DHM, and 0.9995 for CLP, respectively). The relative standard deviations of the migration time and peak area of the four compounds were 0.37, 3.90, 0.73 and 0.68, and 2.80, 3.50, 1.60 and 3.70%, respectively. The method was successfully applied to determine the four compounds in five cold medicines, the recoveries of the four constituents ranging between 91 and 109%.
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Separation and determination of the anthraquinones in Xanthophytum attopvensis pierre by Nonaqueous Capillary Electrophoresis.
Talanta, 2005Co-Authors: Xingguo ChenAbstract:Abstract A Nonaqueous Capillary Electrophoresis (NACE) method with direct on-column UV detection has been developed for the separation of the pharmaceutically important anthraquinones from the total grass of Xanthophytum attopvensis pierre extract. The separation of three main anthraquinones (1-hydroxy-2-methoxy-3-hydroxymethyl-9, 10-anthraquinone-1- O -β- d -glucoside ( 1 ), rubiadin- 1-methylether ( 2 ) and 1-methoxy-2-formyl-3-hydroxy-9, 10-anthraquinone ( 3 )) was optimized with respect to concentration of sodium cholate (SC) and acetic acid, addition of acetonitrile (ACN), and applied voltage. Baseline separation was obtained for the three analytes within 5 min using a running buffer containing 50 mM sodium cholate (SC), 1.0% acetic acid and 40% ACN in methanol. The method of NACE for the separation and determination of bioactive ingredient in traditional Chinese medicines was discussed.
J. -l. Veuthey - One of the best experts on this subject based on the ideXlab platform.
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Nonaqueous Capillary Electrophoresis electrospray mass spectrometry for the analysis of fluoxetine and its related compounds
Electrophoresis, 2002Co-Authors: S. Cherkaoui, J. -l. VeutheyAbstract:The potential of Nonaqueous Capillary Electrophoresis was investigated for the simultaneous separation of fluoxetine hydrochloride, its meta-isomer, and other related compounds. The resolution of these compounds was compared in aqueous and Nonaqueous media. Baseline separation of the studied solutes required a buffer electrolyte solution composed of 25 mM ammonium acetate and 1 M acetic acid in acetonitrile, an applied voltage of 30 kV and a temperature of 20 degrees C. Selectivity was considerably affected by the nature of the solvent (water, methanol, and acetonitrile). Moreover, substituting acetate by formate in the background electrolyte resulted in migration time changes, which were attributed to an ion-pairing phenomenon. Finally, the method was successfully coupled on-line with electrospray ionization-mass spectrometry (ESI-MS) and allowed significant selectivity and sensitivity enhancement. The effect of ESI-MS parameters, such as nebulizing gas pressure, sheath liquid composition and flow rate, on resolution and method sensitivity was also discussed.
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Nonaqueous Capillary Electrophoresis‐electrospray‐ mass spectrometry for the analysis of fluoxetine and its related compounds
Electrophoresis, 2002Co-Authors: S. Cherkaoui, J. -l. VeutheyAbstract:The potential of Nonaqueous Capillary Electrophoresis was investigated for the simultaneous separation of fluoxetine hydrochloride, its meta-isomer, and other related compounds. The resolution of these compounds was compared in aqueous and Nonaqueous media. Baseline separation of the studied solutes required a buffer electrolyte solution composed of 25 mM ammonium acetate and 1 M acetic acid in acetonitrile, an applied voltage of 30 kV and a temperature of 20 degrees C. Selectivity was considerably affected by the nature of the solvent (water, methanol, and acetonitrile). Moreover, substituting acetate by formate in the background electrolyte resulted in migration time changes, which were attributed to an ion-pairing phenomenon. Finally, the method was successfully coupled on-line with electrospray ionization-mass spectrometry (ESI-MS) and allowed significant selectivity and sensitivity enhancement. The effect of ESI-MS parameters, such as nebulizing gas pressure, sheath liquid composition and flow rate, on resolution and method sensitivity was also discussed.
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Rapid separation of basic drugs by Nonaqueous Capillary Electrophoresis
Chromatographia, 2000Co-Authors: S. Cherkaoui, L. Geiser, J. -l. VeutheyAbstract:Nonaqueous Capillary Electrophoresis (NACE) has been used to achieve rapid separations of basic drugs. A high electric field was obtained by using short capillaries. Baseline separations of basic drugs, including amphetamines, tropane alkaloids and local anesthetics, were achieved in 1 min by selection of the appropriate organic solvent and electrolyte composition. Thus, high-throughput analyses can be performed. Peak efficiency up to 9154 theoretical plates s^−1 was achieved in a separation performed at 923V cm^−1. No discernible loss in resolution was observed when a conventional Capillary (64.5cm) was replaced by a short (32.5 cm) Capillary.
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Development and robustness testing of a Nonaqueous Capillary Electrophoresis method for the analysis of nonsteroidal anti-inflammatory drugs.
Journal of chromatography. A, 2000Co-Authors: S. Cherkaoui, J. -l. VeutheyAbstract:Nine non steroidal anti-inflammatory drugs were simultaneously separated by Nonaqueous Capillary Electrophoresis with a methanol-acetonitrile (40:60, v/v) mixture containing 20 mM ammonium acetate. The effect of solvent composition, electrolyte nature and concentration on the electrophoretic behavior of the selected drugs was systematically studied. Investigated electrolytes were ammonium, lithium and sodium acetate. Modification of the solvent and/or the electrolyte composition was found to alter the migration order of the pharmaceutical drugs. Finally, to assess method robustness, three sensitive electrophoretic parameters as well as their interactions were evaluated using a full factorial design at two levels.
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Rapid separation of basic drugs by Nonaqueous Capillary Electrophoresis
Chromatographia, 2000Co-Authors: S. Cherkaoui, L. Geiser, J. -l. VeutheyAbstract:A simple method for the separation and characterization of a group of nine basic compounds, comprising seven tricyclic antidepressant and two bronchodilator drugs, by Nonaqueous Capillary Electrophoresis (NACE) employing ultraviolet and mass spectrometry detection is described. After optimization of the Electrophoresis separation conditions, including the compositions of the electrolyte and the organic solvent, a reliable separation of all nine basic analytes was achieved in 80 mM ammonium formate dissolved in a methanol-acetonitrite (80:20 v/v) mixture, having an apparent pH of 8.7. The volatile Nonaqueous electrolyte system used with a normal electroosmotic flow polarity also provided an optimal separation condition for the characterization of the analytes by mass spectrometry. When results were compared with reversed-phase gradient and isocratic high-performance liquid chromatography (HPLC) methods, the NACE method provided greater efficiency, achieving baseline resolution for all nine basic compounds in less than 30 min. The NACE method is suitable for use as a routine procedure for the rapid separation and characterization of basic compounds and is a viable alternative to HPLC for the separation of a wide range of pharmaceutical drugs
Cheng Huang Lin - One of the best experts on this subject based on the ideXlab platform.
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Stacking and low‐temperature technique in Nonaqueous Capillary Electrophoresis for the analysis of 3,4‐methylenedioxymethamphetamine
ELECTROPHORESIS, 2004Co-Authors: Chih Hsin Tsai, Ju-tsung Liu, Ching Fang, Cheng Huang LinAbstract:Low-temperature and ambient-temperature Nonaqueous stacking techniques in Capillary Electrophoresis (CE) are described for the first time. A low-temperature bath was used to control the temperature from ambient to subzero degrees, by which a novel hyphenated method, low-temperature bath-Nonaqueous Capillary Electrophoresis stacking (LTB-NACE stacking) is demonstrated. 3,4-Methylenedioxymethamphetamine (3,4-MDMA) was determined at a concentration of 4.7×10−6 M (at a 92.1% confidence level) by normal Nonaqueous Capillary zone Electrophoresis (NACZE) and this was improved to 2.6×10−8 M and 5.0×10−9 M, respectively, when the NACZE stacking and LTB-NACZE stacking techniques were applied. The content of 3,4-MDMA in an illicit drug and a suspect urine sample was readily detected. Upon application of the LTB to the separation of isomers the resolution (R) for the separation of 2,3-/3,4-MDMA was improved from 0.6 (LTB, 22°C) to 1.6 (LTB, −55°C) and for (+)3,4-MDMA/(−)3,4-MDMA, from 0.4 (LTB, 25°C) to 1.0 (LTB, −10°C).
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Stacking and low-temperature technique in Nonaqueous Capillary Electrophoresis for the analysis of 3,4-methylenedioxymethamphetamine.
Electrophoresis, 2004Co-Authors: Chih Hsin Tsai, Ju-tsung Liu, Ching Fang, Cheng Huang LinAbstract:Low-temperature and ambient-temperature Nonaqueous stacking techniques in Capillary Electrophoresis (CE) are described for the first time. A low-temperature bath was used to control the temperature from ambient to subzero degrees, by which a novel hyphenated method, low-temperature bath-Nonaqueous Capillary Electrophoresis stacking (LTB-NACE stacking) is demonstrated. 3,4-Methylenedioxymethamphetamine (3,4-MDMA) was determined at a concentration of 4.7 x 10(-6) M (at a 92.1% confidence level) by normal Nonaqueous Capillary zone Electrophoresis (NACZE) and this was improved to 2.6 x 10(-8) M and 5.0 x 10(-9) M, respectively, when the NACZE stacking and LTB-NACZE stacking techniques were applied. The content of 3,4-MDMA in an illicit drug and a suspect urine sample was readily detected. Upon application of the LTB to the separation of isomers the resolution (R) for the separation of 2,3-/3,4-MDMA was improved from 0.6 (LTB, 22 degrees C) to 1.6 (LTB, -55 degrees C) and for (+)3,4-MDMA/(-)3,4-MDMA, from 0.4 (LTB, 25 degrees C) to 1.0 (LTB, -10 degrees C).
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Rapid analysis of 3,4-methylenedioxymethamphetamine: a comparison of Nonaqueous Capillary Electrophoresis/fluorescence detection with GC/MS.
Forensic science international, 2002Co-Authors: Ching Fang, Yu-lin Chung, Ju-tsung Liu, Cheng Huang LinAbstract:Because of the increasing use of 3,4-methylenedioxymethamphetamine (3,4-MDMA), a rapid and sensitive analytical technique is required for its detection and determination. Using Nonaqueous Capillary Electrophoresis/fluorescence spectroscopy (NACE/FS) detection, it is possible to determine this drug at the level 0.5 ppm without any pre-treatment in less than 5 min. After liquid-liquid extraction, the sample can be condensed and a detection limit of 3,4-MDMA in urine of 50 ppb (S/N = 3) can be achieved. The precision of the method was evaluated by measuring the repeatability and intermediate precision of migration time and the corrected peak height by comparison with a 3,4-MDMA-D5 internal standard. With the conventional GC/MS method, it is necessary to derivatize the 3,4-MDMA before injection and the GC migration time also is in excess of 20 min. Therefore, NACE/FS represents a good complementary method to GC/MS for use in forensic analysis.
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Rapid analysis of 3,4-methylenedioxymethamphetamine: a comparison of Nonaqueous Capillary Electrophoresis/fluorescence detection with GC/MS
Forensic Science International, 2001Co-Authors: Ching Fang, Yu-lin Chung, Ju-tsung Liu, Cheng Huang LinAbstract:Because of the increasing use of 3,4-methylenedioxymethamphetamine (3,4-MDMA), a rapid and sensitive analytical technique is required for its detection and determination. Using Nonaqueous Capillary Electrophoresis/fluorescence spectroscopy (NACE/FS) detection, it is possible to determine this drug at the level 0.5 ppm without any pre-treatment in less than 5 min. After liquid‐liquid extraction, the sample can be condensed and a detection limit of 3,4-MDMA in urine of 50 ppb (S=N ¼ 3) can be achieved. The precision of the method was evaluated by measuring the repeatability and intermediate precision of migration time and the corrected peak height by comparison with a 3,4-MDMA-D5 internal standard. With the conventional GC/MS method, it is necessary to derivatize the 3,4-MDMA before injection and the GC migration time also is in excess of 20 min. Therefore, NACE/FS represents a good complementary method to GC/MS for use in forensic analysis. # 2002 Elsevier Science Ireland Ltd. All rights reserved.
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on line identification of trans and cis resveratrol by Nonaqueous Capillary Electrophoresis fluorescence spectroscopy at 77 k
Electrophoresis, 2001Co-Authors: Cheng Huang Lin, Yi Hsiu ChenAbstract:This work presents a novel method for the accurate determining trans- and cis-resveratrol (3,5,4'-trihydroxystilbene) by Nonaqueous Capillary Electrophoresis/fluorescence spectroscopy at 77 K. The proposed method permits not only the separation of resveratrol isomers, but also ensures that on-line spectra are readily distinguishable and unambiguously assigned. The experimental results also indicate that the effect of Nonaqueous Capillary Electrophoresis buffer and low-temperature technique increase the detection limit by more than 150-fold.
Zilin Chen - One of the best experts on this subject based on the ideXlab platform.
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analysis of six active components in radix tinosporae by Nonaqueous Capillary Electrophoresis with mass spectrometry
IEEE Journal of Solid-state Circuits, 2017Co-Authors: Yikun Liu, Wei Zhou, Zhenkun Mao, Xiaoyan Liao, Zilin ChenAbstract:Nonaqueous Capillary Electrophoresis with mass spectrometry has advantages for the analysis of active components in herbs. Here, a rapid Nonaqueous Capillary Electrophoresis with mass spectrometry method was developed to separate, identify, and quantify palmatin, columbin, cepharanthine, menisperine, magnoflorine and 20-hydroxyecdysone in Radix Tinosporae. Electrospray ionization MS1-3 spectra of the six components were collected and possible cleavage pathways of main fragment ions were elucidated. The conditions which could affect separation like the composition of running buffer, applied voltage were studied and which could affect the mass spectrometry detection like the composition and flow rate of sheath liquid, the pressure of nitrogen gas, the temperature and flow rate of the dry gas were also optimized. Under the optimized conditions, the correlation coefficient was > 0.99. The relative standard deviations of migration time and peak areas were < 10%. The recoveries were calculated to be 99.31–107.80% in real samples. It has been demonstrated that the proposed method has good potential to be applied to determine the six bioactive components in Radix Tinosporae. This article is protected by copyright. All rights reserved
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Analysis of six active components in Radix tinosporae by Nonaqueous Capillary Electrophoresis with mass spectrometry.
Journal of separation science, 2017Co-Authors: Yikun Liu, Wei Zhou, Zhenkun Mao, Xiaoyan Liao, Zilin ChenAbstract:Nonaqueous Capillary Electrophoresis with mass spectrometry has advantages for the analysis of active components in herbs. Here, a rapid Nonaqueous Capillary Electrophoresis with mass spectrometry method was developed to separate, identify, and quantify palmatin, columbin, cepharanthine, menisperine, magnoflorine and 20-hydroxyecdysone in Radix Tinosporae. Electrospray ionization MS1-3 spectra of the six components were collected and possible cleavage pathways of main fragment ions were elucidated. The conditions which could affect separation like the composition of running buffer, applied voltage were studied and which could affect the mass spectrometry detection like the composition and flow rate of sheath liquid, the pressure of nitrogen gas, the temperature and flow rate of the dry gas were also optimized. Under the optimized conditions, the correlation coefficient was > 0.99. The relative standard deviations of migration time and peak areas were
S. Cherkaoui - One of the best experts on this subject based on the ideXlab platform.
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Nonaqueous Capillary Electrophoresis electrospray mass spectrometry for the analysis of fluoxetine and its related compounds
Electrophoresis, 2002Co-Authors: S. Cherkaoui, J. -l. VeutheyAbstract:The potential of Nonaqueous Capillary Electrophoresis was investigated for the simultaneous separation of fluoxetine hydrochloride, its meta-isomer, and other related compounds. The resolution of these compounds was compared in aqueous and Nonaqueous media. Baseline separation of the studied solutes required a buffer electrolyte solution composed of 25 mM ammonium acetate and 1 M acetic acid in acetonitrile, an applied voltage of 30 kV and a temperature of 20 degrees C. Selectivity was considerably affected by the nature of the solvent (water, methanol, and acetonitrile). Moreover, substituting acetate by formate in the background electrolyte resulted in migration time changes, which were attributed to an ion-pairing phenomenon. Finally, the method was successfully coupled on-line with electrospray ionization-mass spectrometry (ESI-MS) and allowed significant selectivity and sensitivity enhancement. The effect of ESI-MS parameters, such as nebulizing gas pressure, sheath liquid composition and flow rate, on resolution and method sensitivity was also discussed.
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Nonaqueous Capillary Electrophoresis‐electrospray‐ mass spectrometry for the analysis of fluoxetine and its related compounds
Electrophoresis, 2002Co-Authors: S. Cherkaoui, J. -l. VeutheyAbstract:The potential of Nonaqueous Capillary Electrophoresis was investigated for the simultaneous separation of fluoxetine hydrochloride, its meta-isomer, and other related compounds. The resolution of these compounds was compared in aqueous and Nonaqueous media. Baseline separation of the studied solutes required a buffer electrolyte solution composed of 25 mM ammonium acetate and 1 M acetic acid in acetonitrile, an applied voltage of 30 kV and a temperature of 20 degrees C. Selectivity was considerably affected by the nature of the solvent (water, methanol, and acetonitrile). Moreover, substituting acetate by formate in the background electrolyte resulted in migration time changes, which were attributed to an ion-pairing phenomenon. Finally, the method was successfully coupled on-line with electrospray ionization-mass spectrometry (ESI-MS) and allowed significant selectivity and sensitivity enhancement. The effect of ESI-MS parameters, such as nebulizing gas pressure, sheath liquid composition and flow rate, on resolution and method sensitivity was also discussed.
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Rapid separation of basic drugs by Nonaqueous Capillary Electrophoresis
Chromatographia, 2000Co-Authors: S. Cherkaoui, L. Geiser, J. -l. VeutheyAbstract:Nonaqueous Capillary Electrophoresis (NACE) has been used to achieve rapid separations of basic drugs. A high electric field was obtained by using short capillaries. Baseline separations of basic drugs, including amphetamines, tropane alkaloids and local anesthetics, were achieved in 1 min by selection of the appropriate organic solvent and electrolyte composition. Thus, high-throughput analyses can be performed. Peak efficiency up to 9154 theoretical plates s^−1 was achieved in a separation performed at 923V cm^−1. No discernible loss in resolution was observed when a conventional Capillary (64.5cm) was replaced by a short (32.5 cm) Capillary.
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Development and robustness testing of a Nonaqueous Capillary Electrophoresis method for the analysis of nonsteroidal anti-inflammatory drugs.
Journal of chromatography. A, 2000Co-Authors: S. Cherkaoui, J. -l. VeutheyAbstract:Nine non steroidal anti-inflammatory drugs were simultaneously separated by Nonaqueous Capillary Electrophoresis with a methanol-acetonitrile (40:60, v/v) mixture containing 20 mM ammonium acetate. The effect of solvent composition, electrolyte nature and concentration on the electrophoretic behavior of the selected drugs was systematically studied. Investigated electrolytes were ammonium, lithium and sodium acetate. Modification of the solvent and/or the electrolyte composition was found to alter the migration order of the pharmaceutical drugs. Finally, to assess method robustness, three sensitive electrophoretic parameters as well as their interactions were evaluated using a full factorial design at two levels.
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Rapid separation of basic drugs by Nonaqueous Capillary Electrophoresis
Chromatographia, 2000Co-Authors: S. Cherkaoui, L. Geiser, J. -l. VeutheyAbstract:A simple method for the separation and characterization of a group of nine basic compounds, comprising seven tricyclic antidepressant and two bronchodilator drugs, by Nonaqueous Capillary Electrophoresis (NACE) employing ultraviolet and mass spectrometry detection is described. After optimization of the Electrophoresis separation conditions, including the compositions of the electrolyte and the organic solvent, a reliable separation of all nine basic analytes was achieved in 80 mM ammonium formate dissolved in a methanol-acetonitrite (80:20 v/v) mixture, having an apparent pH of 8.7. The volatile Nonaqueous electrolyte system used with a normal electroosmotic flow polarity also provided an optimal separation condition for the characterization of the analytes by mass spectrometry. When results were compared with reversed-phase gradient and isocratic high-performance liquid chromatography (HPLC) methods, the NACE method provided greater efficiency, achieving baseline resolution for all nine basic compounds in less than 30 min. The NACE method is suitable for use as a routine procedure for the rapid separation and characterization of basic compounds and is a viable alternative to HPLC for the separation of a wide range of pharmaceutical drugs
