The Experts below are selected from a list of 186 Experts worldwide ranked by ideXlab platform
Yukui Zhang - One of the best experts on this subject based on the ideXlab platform.
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Integration of normal phase liquid chromatography with supercritical fluid chromatography for analysis of fruiting bodies of Ganoderma lucidum
Journal of separation science, 2010Co-Authors: Liang Gao, Jie Zhang, Zhen Liang, Weibing Zhang, Lihua Zhang, Yushu Huo, Yichu Shan, Yukui ZhangAbstract:In this study, a comprehensive 2-D chromatography was constructed, consisting of normal phase LC (NPLC) with a CN column as the first dimension, and supercritical fluid chromatography (SFC), with a Merck Chromolith Flash C(18) column as the second dimension, which were connected by a 10-port, dual-Position Valve controlled automatically by a self-designed software. Such platform was applied into the analysis of the fruiting bodies of Ganoderma lucidum, a traditional Chinese medicine, and within 2 h analysis, the obtained peak capacity of the 2-D-NPLC-SFC system was about 350, obviously higher than that of each dimension. These results demonstrate that 2-D-NPLC-SFC is not only of good orthogonality, but also of high throughput for the analysis of complex samples.
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Separation and identification of compounds in Adinandra nitida by comprehensive two-dimensional liquid chromatography coupled to atmospheric pressure chemical ionization source ion trap tandem mass spectrometry.
Analytical and bioanalytical chemistry, 2006Co-Authors: Jie Zhang, Dingyin Tao, Jicheng Duan, Zhen Liang, Weibing Zhang, Lihua Zhang, Yushu Huo, Yukui ZhangAbstract:A comprehensive two-dimensional liquid chromatographic (2D-LC) separation system based on the combination of a CN column and a Merck Chromolith Flash reversed-phase column was developed for the separation of components in Adinandra nitida, one type of traditional Chinese medicine (TCM). The two dimensions were connected by a ten-port, dual-Position Valve controlled automatically by software written in-house. The effluents were detected by both ultraviolet and atmospheric pressure chemical ionization source ion trap tandem mass spectrometry (MS). The calculated peak capacity of the 2D-LC-MS/MS system was above 1240. More than 57 components were resolved in the methanol extract from Adinandra nitida leaves, and five of these were identified based on their relative retention times, molecular weights and MS/MS spectra.
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On-line hyphenation of supercritical fluid extraction and two-dimensional high performance liquid chromatography-atmospheric pressure chemical ionization tandem mass spectrometer for the analysis of Ganoderma lucidum.
Journal of separation science, 2006Co-Authors: Jie Zhang, Jicheng Duan, Zhen Liang, Weibing Zhang, Lihua Zhang, Yushu Huo, Yukui ZhangAbstract:A novel on-line system combining supercritical fluid extraction (SFE) and two-dimensional high performance liquid chromatography (2D-HPLC) was developed. A trap column and two three-port Valves were employed to couple SFE and 2D-HPLC system, which was composed of a CN column and a monolithic silica column, connected by a 10-port dual-Position Valve. The analytes extracted by supercritical CO2 were completely transferred to the 2D-HPLC system. After separation in two orthogonal modes, the eluents were delivered to APCI-tandem-MS for identification of the samples. In this way, sample preparation, separation, detection, and identification were integrated into an on-line system permitting analysis of the fruiting bodies of Ganoderma lucidum, and at least 73 components in the extract were resolved with calculated peak capacity of up to 1643.
Luigi Mondello - One of the best experts on this subject based on the ideXlab platform.
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Optimization of a Comprehensive Two-Dimensional Normal-Phase and Reversed-Phase Liquid Chromatography System
Journal of chromatographic science, 2006Co-Authors: Paola Dugo, Giovanni Dugo, Maria Del Mar Ramírez Fernández, Antonella Cotroneo, Luigi MondelloAbstract:The present investigation is based on the evaluation of the performance of a comprehensive two-dimensional liquid chromatography (LCxLC) system during method optimization. The LCxLC set-up, operated in normal phase (NP) mode (adsorption) in the first dimension (1D) and reversed-phase (RP) mode in the second dimension (2D), is equipped with a 1D microbore silica column and a 2D monolithic C(18) column with a 10-port two Position Valve as the interface. A photodiode array detector is used after the 2D separation. A possible cause of peak distorsion because of the immiscibility of the mobile phases employed in the two dimensions is resolved. The optimization of the analytical run time and flow rate for both dimensions and the initial gradient in the 2D is carried out with various standard compounds. The potential and versatility of this LCxLC approach is demonstrated through the separation of 11 standard components, most of them allergens. The latter, which are characterized by a scattered distribution on the 2D space plane, underwent separation on both a hydrophobicity and polarity basis.
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Development of different comprehensive two dimensional systems for the separation of phenolic antioxidants.
Journal of separation science, 2006Co-Authors: Francesco Cacciola, Pavel Jandera, Eva Blahová, Luigi MondelloAbstract:Three different comprehensive 2-D HPLC systems for the separation of phenolic antioxidants have been developed on the basis of different selectivities of a PEG-silica column in the first dimension and a packed or monolithic C 18 or a ZR-CARBON column, respectively, in the second dimension. Two-dimensional comprehensive liquid chromatography using a serially connected short PEG-silica column and a conventional C 18 -silica or a ZR-CARBON column in the second dimension was tested to improve the resolution of the earlier eluting compounds in the first dimension. Various types of interface were used to connect the columns in the first and in the second dimension: i) two injection sampling loops of 100 μL in conventional arrangement; ii) a 10-port 2-Position Valve equipped with two trapping X-Terra columns instead of loops; and iii) two analytical D2 columns in parallel. The mobile phase in the first dimension has a lower elution strength than in the second dimension, allowing band compression of the solutes transferred from the first to the second dimension. This effect was enhanced using trapping columns instead of sampling loops as the interface between the two dimensions, thus allowing a decrease in the time of analysis. These systems were used for the analysis of beer samples. The relative location of the components in the 2-D retention plane varied in relation to their chemical structure in each instrumental set-up and allowed positive peak identification.
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Comprehensive two-dimensional normal-phase (adsorption)-reversed-phase liquid chromatography.
Analytical chemistry, 2004Co-Authors: Paola Dugo, Olinda Favoino, Rosario Luppino, Giovanni Dugo, Luigi MondelloAbstract:A comprehensive two-dimensional HPLC system has been developed. It is based on the use of a microbore silica column operated in normal-phase (adsorption) mode (NP) in the first dimension and a monolithic type C18 column operated in reversed-phase (RP) mode in the second dimension. The interface was a 10-port, 2-Position Valve equipped with two storage loops. The first column was operated at a flow rate of 20 μL/min in isocratic mode, while the monolithic column flow rate was 4 mL/min and was operated in gradient mode. The sample loops had a volume of 20 μL each, and the analysis time in the second dimension was 1 min. In this way, every fraction from the first dimension was transferred on-line to the second dimension switching the automated Valve every minute. A photodiode array detector has been used after the secondary column. The use of normal- and reversed-phase mode in the two dimensions can be helpful in the separation of complex mixtures of a natural origin that contain uncharged molecules of compa...
Weibing Zhang - One of the best experts on this subject based on the ideXlab platform.
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Integration of normal phase liquid chromatography with supercritical fluid chromatography for analysis of fruiting bodies of Ganoderma lucidum
Journal of separation science, 2010Co-Authors: Liang Gao, Jie Zhang, Zhen Liang, Weibing Zhang, Lihua Zhang, Yushu Huo, Yichu Shan, Yukui ZhangAbstract:In this study, a comprehensive 2-D chromatography was constructed, consisting of normal phase LC (NPLC) with a CN column as the first dimension, and supercritical fluid chromatography (SFC), with a Merck Chromolith Flash C(18) column as the second dimension, which were connected by a 10-port, dual-Position Valve controlled automatically by a self-designed software. Such platform was applied into the analysis of the fruiting bodies of Ganoderma lucidum, a traditional Chinese medicine, and within 2 h analysis, the obtained peak capacity of the 2-D-NPLC-SFC system was about 350, obviously higher than that of each dimension. These results demonstrate that 2-D-NPLC-SFC is not only of good orthogonality, but also of high throughput for the analysis of complex samples.
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Establishment and application of a two-dimensional liquid chromatographic system (NPLC x RPLC)
Se pu = Chinese journal of chromatography, 2008Co-Authors: Tao Lan, Fenglong Jiao, Tao Tang, Fengyun Wang, Weibing ZhangAbstract:A two-dimensional liquid chromatographic system (NPLC x RPLC) has been developed. Normal phase liquid chromatography (NPLC) with a Hypersil SiO2 column (50 mm x 4.6 mm) was used as the first dimension, and reversed-phase liquid chromatography (RPLC) with a Kromasil C18 column (250 mm x 4.6 mm) was used as the second dimension. The interface was a ten-port, two-Position Valve with two storage loops. As to improve the compatibility of the two dimensional mobile phase and be good for adjusting the selectivity of separation, 1,4-dioxane was used in the mobile phase of the first dimension, and isopropyl alcohol was used in the mobile phase of the second dimension based on the characters of the organic solvents. By raising the temperature of the second dimension, the incompatibility of the two dimensional mobile phases was avoided. A Chinese potent medicine, Zhengtian Wan, was analyzed by this system. The total peak capacity reached 1 220.
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Separation and identification of compounds in Adinandra nitida by comprehensive two-dimensional liquid chromatography coupled to atmospheric pressure chemical ionization source ion trap tandem mass spectrometry.
Analytical and bioanalytical chemistry, 2006Co-Authors: Jie Zhang, Dingyin Tao, Jicheng Duan, Zhen Liang, Weibing Zhang, Lihua Zhang, Yushu Huo, Yukui ZhangAbstract:A comprehensive two-dimensional liquid chromatographic (2D-LC) separation system based on the combination of a CN column and a Merck Chromolith Flash reversed-phase column was developed for the separation of components in Adinandra nitida, one type of traditional Chinese medicine (TCM). The two dimensions were connected by a ten-port, dual-Position Valve controlled automatically by software written in-house. The effluents were detected by both ultraviolet and atmospheric pressure chemical ionization source ion trap tandem mass spectrometry (MS). The calculated peak capacity of the 2D-LC-MS/MS system was above 1240. More than 57 components were resolved in the methanol extract from Adinandra nitida leaves, and five of these were identified based on their relative retention times, molecular weights and MS/MS spectra.
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On-line hyphenation of supercritical fluid extraction and two-dimensional high performance liquid chromatography-atmospheric pressure chemical ionization tandem mass spectrometer for the analysis of Ganoderma lucidum.
Journal of separation science, 2006Co-Authors: Jie Zhang, Jicheng Duan, Zhen Liang, Weibing Zhang, Lihua Zhang, Yushu Huo, Yukui ZhangAbstract:A novel on-line system combining supercritical fluid extraction (SFE) and two-dimensional high performance liquid chromatography (2D-HPLC) was developed. A trap column and two three-port Valves were employed to couple SFE and 2D-HPLC system, which was composed of a CN column and a monolithic silica column, connected by a 10-port dual-Position Valve. The analytes extracted by supercritical CO2 were completely transferred to the 2D-HPLC system. After separation in two orthogonal modes, the eluents were delivered to APCI-tandem-MS for identification of the samples. In this way, sample preparation, separation, detection, and identification were integrated into an on-line system permitting analysis of the fruiting bodies of Ganoderma lucidum, and at least 73 components in the extract were resolved with calculated peak capacity of up to 1643.
Jie Zhang - One of the best experts on this subject based on the ideXlab platform.
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Integration of normal phase liquid chromatography with supercritical fluid chromatography for analysis of fruiting bodies of Ganoderma lucidum
Journal of separation science, 2010Co-Authors: Liang Gao, Jie Zhang, Zhen Liang, Weibing Zhang, Lihua Zhang, Yushu Huo, Yichu Shan, Yukui ZhangAbstract:In this study, a comprehensive 2-D chromatography was constructed, consisting of normal phase LC (NPLC) with a CN column as the first dimension, and supercritical fluid chromatography (SFC), with a Merck Chromolith Flash C(18) column as the second dimension, which were connected by a 10-port, dual-Position Valve controlled automatically by a self-designed software. Such platform was applied into the analysis of the fruiting bodies of Ganoderma lucidum, a traditional Chinese medicine, and within 2 h analysis, the obtained peak capacity of the 2-D-NPLC-SFC system was about 350, obviously higher than that of each dimension. These results demonstrate that 2-D-NPLC-SFC is not only of good orthogonality, but also of high throughput for the analysis of complex samples.
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Separation and identification of compounds in Adinandra nitida by comprehensive two-dimensional liquid chromatography coupled to atmospheric pressure chemical ionization source ion trap tandem mass spectrometry.
Analytical and bioanalytical chemistry, 2006Co-Authors: Jie Zhang, Dingyin Tao, Jicheng Duan, Zhen Liang, Weibing Zhang, Lihua Zhang, Yushu Huo, Yukui ZhangAbstract:A comprehensive two-dimensional liquid chromatographic (2D-LC) separation system based on the combination of a CN column and a Merck Chromolith Flash reversed-phase column was developed for the separation of components in Adinandra nitida, one type of traditional Chinese medicine (TCM). The two dimensions were connected by a ten-port, dual-Position Valve controlled automatically by software written in-house. The effluents were detected by both ultraviolet and atmospheric pressure chemical ionization source ion trap tandem mass spectrometry (MS). The calculated peak capacity of the 2D-LC-MS/MS system was above 1240. More than 57 components were resolved in the methanol extract from Adinandra nitida leaves, and five of these were identified based on their relative retention times, molecular weights and MS/MS spectra.
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On-line hyphenation of supercritical fluid extraction and two-dimensional high performance liquid chromatography-atmospheric pressure chemical ionization tandem mass spectrometer for the analysis of Ganoderma lucidum.
Journal of separation science, 2006Co-Authors: Jie Zhang, Jicheng Duan, Zhen Liang, Weibing Zhang, Lihua Zhang, Yushu Huo, Yukui ZhangAbstract:A novel on-line system combining supercritical fluid extraction (SFE) and two-dimensional high performance liquid chromatography (2D-HPLC) was developed. A trap column and two three-port Valves were employed to couple SFE and 2D-HPLC system, which was composed of a CN column and a monolithic silica column, connected by a 10-port dual-Position Valve. The analytes extracted by supercritical CO2 were completely transferred to the 2D-HPLC system. After separation in two orthogonal modes, the eluents were delivered to APCI-tandem-MS for identification of the samples. In this way, sample preparation, separation, detection, and identification were integrated into an on-line system permitting analysis of the fruiting bodies of Ganoderma lucidum, and at least 73 components in the extract were resolved with calculated peak capacity of up to 1643.
Dongxing Yuan - One of the best experts on this subject based on the ideXlab platform.
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Automated spectrophotometric determination of carbonate ion concentration in seawater using a portable syringe pump based analyzer
Marine Chemistry, 2019Co-Authors: Qipei Shangguan, Huilin Shu, Kunning Lin, Robert H. Byrne, Dongxing YuanAbstract:Abstract Observations of seawater carbonate ion concentrations are critical to assess the ecological effects of ocean acidification. Nevertheless, currently available methods are labor intensive or too complex for field applications. Here, we report the design and performance of the first fully automated portable carbonate ion analyzer. Measurements are based on reaction of carbonate and chloride ions with Pb(II) followed by quantitative UV spectrophotometric detection of the PbCO 3 0 complex. The core hardware is a syringe pump equipped with a multi-Position Valve that is controlled by software written in LabVIEW. Measurement precision is 1.1% ( n = 13) with a measurement frequency of 12 h −1 . The analyzer was used to continuously monitor carbonate ion concentration variations in a 2500 L coral reef tank for five days (test 1), and used for shipboard underway and vertical profile analysis during a 13-day cruise (test 2). The analyzer attained a combined standard uncertainty of 3.0%, which meets the Global Ocean Acidification Observing Network's “weather level” goal. Through use of a syringe pump mechanism for mixing seawater and reagent solution, the analyzer is robust, functionally flexible, and quite suitable for continuous environmental monitoring under harsh conditions.
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Determination of nine emerging pesticides at trace level in aqueous samples using fully automated on-line solid phase extraction coupled with liquid chromatography-mass spectrometry
International Journal of Environmental Analytical Chemistry, 2013Co-Authors: Qian Sun, Min Zhang, Dongxing Yuan, Zuliang ChenAbstract:On-line solid phase extraction (SPE) coupled to liquid chromatography-mass spectrometry (LC-MS) offers an easy and fast strategy to analyze the organic contaminants in environmental samples with high sensitivity and selectivity. This paper described an in-house designed on-line SPE system and an on-line SPE-LC-MS method for the determination of pesticides at trace levels in water samples. The system was assembled from an eight-Position Valve, a piston pump, a six-port Valve and a C18 SPE column, and significantly reduced analysis time by achieving full automation. Moreover, the use of a large enrichment volume (50 mL) significantly enhanced method sensitivity. Using this on-line SPE system, an on-line SPE-LC-MS method was developed for the determination of nine pesticides at trace levels in lake water and seawater sample. Under optimized conditions, method detection limits (MDLs) were 1.00–10.0 ng L−1.