The Experts below are selected from a list of 282 Experts worldwide ranked by ideXlab platform
Claire Elfakir - One of the best experts on this subject based on the ideXlab platform.
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approach to hydrophilic interaction Chromatography Column selection application to neurotransmitters analysis
Journal of Chromatography A, 2010Co-Authors: Raluca Ioana Chirita, Caroline West, Adriana Luminita Finaru, Claire ElfakirAbstract:This paper presents the comparison between 12 hydrophilic interaction liquid Chromatography Columns that are commercially available. The main factors influencing the retention and selectivity toward 12 neurotransmitters for these different HILIC systems have been studied. For additional information, the retention data have been analyzed statistically by factor analysis. Principal component analyses (PCA) were calculated to evidence different separation behaviour between the stationary phases, based on the retention data measured for three compound classes: anionic acidic compounds, cationic basic compounds and zwitterionic amino acids. Finally, a generic procedure is suggested for optimization of HILIC analyses, depending on the ionization state of the analytes.
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Approach to hydrophilic interaction Chromatography Column selection: Application to neurotransmitters analysis
Journal of Chromatography A, 2010Co-Authors: Raluca Ioana Chirita, Caroline West, Adriana Luminita Finaru, Claire ElfakirAbstract:This paper presents the comparison between 12 hydrophilic interaction liquid Chromatography Columns that are commercially available. The main factors influencing the retention and selectivity toward 12 neurotransmitters for these different HILIC systems have been studied. For additional information, the retention data have been analyzed statistically by factor analysis. Principal component analyses (PCA) were calculated to evidence different separation behaviour between the stationary phases, based on the retention data measured for three compound classes: anionic acidic compounds, cationic basic compounds and zwitterionic amino acids. Finally, a generic procedure is suggested for optimization of HILIC analyses, depending on the ionization state of the analytes. © 2010 Elsevier B.V.
Xing Chen - One of the best experts on this subject based on the ideXlab platform.
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an improved photoionization detector with a micro gas Chromatography Column for portable rapid gas Chromatography system
Sensors and Actuators B-chemical, 2013Co-Authors: Fengying Guan, Xing Chen, Lulu Zhang, Jian ChenAbstract:Abstract An improved portable photoionization detector (PID) was proposed in this manuscript. A novel structure named “nozzle” with a volume slightly less than the ionization chamber was positioned in the center of the chamber, dramatically reducing the ionization chamber volume and improving device sensitivity. An annular accelerating electrode was embedded in the nozzle groove to shield from vacuum ultraviolet (VUV) light radiation, decreasing background noises. Then the improved PID combined with a high separation efficiently micro gas Chromatography (GC) Column was used to construct a portable rapid GC system. The results indicated that the proposed PID in this study demonstrated an ultra low background noise (≤1 × 10−14 A) and a small baseline drift. Moreover, the proposed PID was characterized with a response time less than 30 ms and a large linear range of 106. The proposed system was used to detect gas mixtures with a detection limit less than 5 ppb.
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fabrication and characterization of microelectromechanical systems based gas Chromatography Column with embedded micro posts for separation of environmental carcinogens
Journal of Chromatography A, 2013Co-Authors: Xing Chen, Lulu Zhang, Hui LiAbstract:Abstract In this paper, a micro gas Chromatography (μGC) Column with embedded micro-posts was developed for increasing overall surface area of the Columns which is able to support more of the stationary phase and reducing the effective width of the Column, leading to higher separation efficiency. The proposed Columns have a higher sample capacity as the overall surface area is about 3 times larger than that of open Columns with the same dimensions. In order to achieve an even flow velocity in the channels, the location of the micro-posts in the linear channels and the configuration of curved channels were optimized by numerical simulation. The results have indicated that the proposed Column separated 5 environmental carcinogens in less than 50 s, achieved a separation efficiency of about 9500 plates/m and eluted highly symmetrical Gaussian peaks.
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a high resolution mems based gas Chromatography Column for the analysis of benzene and toluene gaseous mixtures
Sensors and Actuators B-chemical, 2009Co-Authors: Yutai Li, Jian Chen, Lulu Zhang, Hui Li, Xing ChenAbstract:Abstract his paper reports a high resolution gas Chromatography (GC) Column based on micro electro mechanical systems (MEMS) technology. This 6.0 m long, 100 μm wide, and 100 μm deep Column was fabricated using deep reactive-ion etching (DRIE) to form channels for gas separation, and the channels were sealed with Pyrex 7740 glass by using anode bonding. After the GC Column was coated with dimethyl polysiloxane (OV-1) as the stationary phase, benzene and toluene were successfully separated in less than 185 s. The resolution of benzene and toluene was 6.33, which was higher than any previously reported values to our best knowledge. The tailing factors of benzene and toluene were 1.13 and 1.20, respectively, and the number of theoretical plates of toluene was 4850. The system is applicable as a portable device for ambient air quality monitoring and industrial exhaust gas analysis.
Raluca Ioana Chirita - One of the best experts on this subject based on the ideXlab platform.
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approach to hydrophilic interaction Chromatography Column selection application to neurotransmitters analysis
Journal of Chromatography A, 2010Co-Authors: Raluca Ioana Chirita, Caroline West, Adriana Luminita Finaru, Claire ElfakirAbstract:This paper presents the comparison between 12 hydrophilic interaction liquid Chromatography Columns that are commercially available. The main factors influencing the retention and selectivity toward 12 neurotransmitters for these different HILIC systems have been studied. For additional information, the retention data have been analyzed statistically by factor analysis. Principal component analyses (PCA) were calculated to evidence different separation behaviour between the stationary phases, based on the retention data measured for three compound classes: anionic acidic compounds, cationic basic compounds and zwitterionic amino acids. Finally, a generic procedure is suggested for optimization of HILIC analyses, depending on the ionization state of the analytes.
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Approach to hydrophilic interaction Chromatography Column selection: Application to neurotransmitters analysis
Journal of Chromatography A, 2010Co-Authors: Raluca Ioana Chirita, Caroline West, Adriana Luminita Finaru, Claire ElfakirAbstract:This paper presents the comparison between 12 hydrophilic interaction liquid Chromatography Columns that are commercially available. The main factors influencing the retention and selectivity toward 12 neurotransmitters for these different HILIC systems have been studied. For additional information, the retention data have been analyzed statistically by factor analysis. Principal component analyses (PCA) were calculated to evidence different separation behaviour between the stationary phases, based on the retention data measured for three compound classes: anionic acidic compounds, cationic basic compounds and zwitterionic amino acids. Finally, a generic procedure is suggested for optimization of HILIC analyses, depending on the ionization state of the analytes. © 2010 Elsevier B.V.
Lulu Zhang - One of the best experts on this subject based on the ideXlab platform.
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an improved photoionization detector with a micro gas Chromatography Column for portable rapid gas Chromatography system
Sensors and Actuators B-chemical, 2013Co-Authors: Fengying Guan, Xing Chen, Lulu Zhang, Jian ChenAbstract:Abstract An improved portable photoionization detector (PID) was proposed in this manuscript. A novel structure named “nozzle” with a volume slightly less than the ionization chamber was positioned in the center of the chamber, dramatically reducing the ionization chamber volume and improving device sensitivity. An annular accelerating electrode was embedded in the nozzle groove to shield from vacuum ultraviolet (VUV) light radiation, decreasing background noises. Then the improved PID combined with a high separation efficiently micro gas Chromatography (GC) Column was used to construct a portable rapid GC system. The results indicated that the proposed PID in this study demonstrated an ultra low background noise (≤1 × 10−14 A) and a small baseline drift. Moreover, the proposed PID was characterized with a response time less than 30 ms and a large linear range of 106. The proposed system was used to detect gas mixtures with a detection limit less than 5 ppb.
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fabrication and characterization of microelectromechanical systems based gas Chromatography Column with embedded micro posts for separation of environmental carcinogens
Journal of Chromatography A, 2013Co-Authors: Xing Chen, Lulu Zhang, Hui LiAbstract:Abstract In this paper, a micro gas Chromatography (μGC) Column with embedded micro-posts was developed for increasing overall surface area of the Columns which is able to support more of the stationary phase and reducing the effective width of the Column, leading to higher separation efficiency. The proposed Columns have a higher sample capacity as the overall surface area is about 3 times larger than that of open Columns with the same dimensions. In order to achieve an even flow velocity in the channels, the location of the micro-posts in the linear channels and the configuration of curved channels were optimized by numerical simulation. The results have indicated that the proposed Column separated 5 environmental carcinogens in less than 50 s, achieved a separation efficiency of about 9500 plates/m and eluted highly symmetrical Gaussian peaks.
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a high resolution mems based gas Chromatography Column for the analysis of benzene and toluene gaseous mixtures
Sensors and Actuators B-chemical, 2009Co-Authors: Yutai Li, Jian Chen, Lulu Zhang, Hui Li, Xing ChenAbstract:Abstract his paper reports a high resolution gas Chromatography (GC) Column based on micro electro mechanical systems (MEMS) technology. This 6.0 m long, 100 μm wide, and 100 μm deep Column was fabricated using deep reactive-ion etching (DRIE) to form channels for gas separation, and the channels were sealed with Pyrex 7740 glass by using anode bonding. After the GC Column was coated with dimethyl polysiloxane (OV-1) as the stationary phase, benzene and toluene were successfully separated in less than 185 s. The resolution of benzene and toluene was 6.33, which was higher than any previously reported values to our best knowledge. The tailing factors of benzene and toluene were 1.13 and 1.20, respectively, and the number of theoretical plates of toluene was 4850. The system is applicable as a portable device for ambient air quality monitoring and industrial exhaust gas analysis.
Jian Chen - One of the best experts on this subject based on the ideXlab platform.
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an improved photoionization detector with a micro gas Chromatography Column for portable rapid gas Chromatography system
Sensors and Actuators B-chemical, 2013Co-Authors: Fengying Guan, Xing Chen, Lulu Zhang, Jian ChenAbstract:Abstract An improved portable photoionization detector (PID) was proposed in this manuscript. A novel structure named “nozzle” with a volume slightly less than the ionization chamber was positioned in the center of the chamber, dramatically reducing the ionization chamber volume and improving device sensitivity. An annular accelerating electrode was embedded in the nozzle groove to shield from vacuum ultraviolet (VUV) light radiation, decreasing background noises. Then the improved PID combined with a high separation efficiently micro gas Chromatography (GC) Column was used to construct a portable rapid GC system. The results indicated that the proposed PID in this study demonstrated an ultra low background noise (≤1 × 10−14 A) and a small baseline drift. Moreover, the proposed PID was characterized with a response time less than 30 ms and a large linear range of 106. The proposed system was used to detect gas mixtures with a detection limit less than 5 ppb.
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a high resolution mems based gas Chromatography Column for the analysis of benzene and toluene gaseous mixtures
Sensors and Actuators B-chemical, 2009Co-Authors: Yutai Li, Jian Chen, Lulu Zhang, Hui Li, Xing ChenAbstract:Abstract his paper reports a high resolution gas Chromatography (GC) Column based on micro electro mechanical systems (MEMS) technology. This 6.0 m long, 100 μm wide, and 100 μm deep Column was fabricated using deep reactive-ion etching (DRIE) to form channels for gas separation, and the channels were sealed with Pyrex 7740 glass by using anode bonding. After the GC Column was coated with dimethyl polysiloxane (OV-1) as the stationary phase, benzene and toluene were successfully separated in less than 185 s. The resolution of benzene and toluene was 6.33, which was higher than any previously reported values to our best knowledge. The tailing factors of benzene and toluene were 1.13 and 1.20, respectively, and the number of theoretical plates of toluene was 4850. The system is applicable as a portable device for ambient air quality monitoring and industrial exhaust gas analysis.