The Experts below are selected from a list of 3015 Experts worldwide ranked by ideXlab platform
Ryszard Lobinski - One of the best experts on this subject based on the ideXlab platform.
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fractionation and speciation of nickel and vanadium in crude oils by size exclusion chromatography icp ms and Normal Phase HPLC icp ms
Journal of Analytical Atomic Spectrometry, 2010Co-Authors: G. Caumette, Brice Bouyssiere, Charles Philippe Lienemann, Isabelle Merdrignac, Ryszard LobinskiAbstract:The coupling of size exclusion chromatography (SEC) and Normal Phase (NP) HPLC using entirely organic mobile Phases (tetrahydrofuran, xylene) with inductively coupled plasma mass spectrometry (ICP MS) were developed and investigated for the molecular distribution of nickel and vanadium in crude oils. The metal species were fractionated by SEC using three columns in series with the increasing porosity (100, 1000 and 100000 A) covering the molecular mass range (in eq. polystyrene) between 300 and 2 × 106 Da. The resolution achieved allowed the discrimination of at least three classes of Ni and V species with varying proportions of the metals as a function of the origin of crude oil, crude oil fraction (asphaltene, maltene) and dilution factor. Normal Phase HPLC-ICP MS allowed the separation of the porphyrin-type fraction as well as separation of the remaining species into three distinct fractions. The metal species in the SEC fractions were found to be sufficiently stable to be collected and preconcentrated to allow the development of a bidimensional chromatography SEC-NP-HPLC-ICPMS for the probing of the metal distribution in crude oils in terms of molecular weight and polarity.
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detection and identification of hydrophilic selenium compounds in selenium rich yeast by size exclusion microbore Normal Phase HPLC with the on line icp ms and electrospray q tof ms detection
Analytica Chimica Acta, 2010Co-Authors: Hugues Preudhomme, Ryszard LobinskiAbstract:Abstract Normal-Phase HPLC and hydrophilic interaction HPLC (HILIC) were investigated for the separation of selenometabolites in a water extract of Se-rich yeast prior to their detection by ICP–MS and identification by electrospray MS/MS. The targeted fraction was a low-abundant fraction co-eluting with salt and sulfur analogues in size-exclusion chromatography which has so far been inaccessible to Se speciation studies. The optimization of the separation conditions resulted in the highest separation efficiency when HILIC was used and elution was carried out isocratically with a low concentration ammonium acetate buffer (1 mM ammonium acetate/10 mM acetic acid) in 80% acetonitrile. Out of 15 peaks observed with the Se-specific ICP–MS detection 12 was identified by electrospray Q-TOF MS/MS (2,3-dihydroxypropionyl (DHP)-Se-methylselenocysteine [M+H] + : 272, Se-methyl-γ-glutamyl-selenocysteinylglycine dioxide [M+H] + : 402, γ-glutamyl-Se-methylselenocysteine [M+H] + : 313; isomers of γ-glutamylselenocystathionine [M+H] + : 400; Se-methyl-selenoglutathione [M+H] + : 370, isomers of N-acetylselenocystathionine [M+H] + : 313, 2,3-DHP-selenohomolanthionine [M+H] + : 373, isomers of 2,3-DHP-selenocystathionine [M+H] + : 359, 2,3-DHP-selenolanthionine [M+H] + : 345 and selenohomolanthionine [M+H] + : 285).
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Fractionation and speciation of nickel and vanadium in crude oils by size exclusion chromatography-ICP MS and Normal Phase HPLC-ICP MS
Journal of Analytical Atomic Spectrometry, 2010Co-Authors: G. Caumette, Brice Bouyssiere, Charles Philippe Lienemann, Isabelle Merdrignac, Ryszard LobinskiAbstract:The coupling of size exclusion chromatography (SEC) and Normal Phase (NP) HPLC using entirely organic mobile Phases (tetrahydrofuran, xylene) with inductively coupled plasma mass spectrometry (ICP MS) were developed and investigated for the molecular distribution of nickel and vanadium in crude oils. The metal species were fractionated by SEC using three columns in series with the increasing porosity (100, 1000 and 100000 A) covering the molecular mass range (in eq. polystyrene) between 300 and 2 [times] 106 Da. The resolution achieved allowed the discrimination of at least three classes of Ni and V species with varying proportions of the metals as a function of the origin of crude oil, crude oil fraction (asphaltene, maltene) and dilution factor. Normal Phase HPLC-ICP MS allowed the separation of the porphyrin-type fraction as well as separation of the remaining species into three distinct fractions. The metal species in the SEC fractions were found to be sufficiently stable to be collected and preconcentrated to allow the development of a bidimensional chromatography SEC-NP-HPLC-ICPMS for the probing of the metal distribution in crude oils in terms of molecular weight and polarity.
G. Caumette - One of the best experts on this subject based on the ideXlab platform.
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fractionation and speciation of nickel and vanadium in crude oils by size exclusion chromatography icp ms and Normal Phase HPLC icp ms
Journal of Analytical Atomic Spectrometry, 2010Co-Authors: G. Caumette, Brice Bouyssiere, Charles Philippe Lienemann, Isabelle Merdrignac, Ryszard LobinskiAbstract:The coupling of size exclusion chromatography (SEC) and Normal Phase (NP) HPLC using entirely organic mobile Phases (tetrahydrofuran, xylene) with inductively coupled plasma mass spectrometry (ICP MS) were developed and investigated for the molecular distribution of nickel and vanadium in crude oils. The metal species were fractionated by SEC using three columns in series with the increasing porosity (100, 1000 and 100000 A) covering the molecular mass range (in eq. polystyrene) between 300 and 2 × 106 Da. The resolution achieved allowed the discrimination of at least three classes of Ni and V species with varying proportions of the metals as a function of the origin of crude oil, crude oil fraction (asphaltene, maltene) and dilution factor. Normal Phase HPLC-ICP MS allowed the separation of the porphyrin-type fraction as well as separation of the remaining species into three distinct fractions. The metal species in the SEC fractions were found to be sufficiently stable to be collected and preconcentrated to allow the development of a bidimensional chromatography SEC-NP-HPLC-ICPMS for the probing of the metal distribution in crude oils in terms of molecular weight and polarity.
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Fractionation and speciation of nickel and vanadium in crude oils by size exclusion chromatography-ICP MS and Normal Phase HPLC-ICP MS
Journal of Analytical Atomic Spectrometry, 2010Co-Authors: G. Caumette, Brice Bouyssiere, Charles Philippe Lienemann, Isabelle Merdrignac, Ryszard LobinskiAbstract:The coupling of size exclusion chromatography (SEC) and Normal Phase (NP) HPLC using entirely organic mobile Phases (tetrahydrofuran, xylene) with inductively coupled plasma mass spectrometry (ICP MS) were developed and investigated for the molecular distribution of nickel and vanadium in crude oils. The metal species were fractionated by SEC using three columns in series with the increasing porosity (100, 1000 and 100000 A) covering the molecular mass range (in eq. polystyrene) between 300 and 2 [times] 106 Da. The resolution achieved allowed the discrimination of at least three classes of Ni and V species with varying proportions of the metals as a function of the origin of crude oil, crude oil fraction (asphaltene, maltene) and dilution factor. Normal Phase HPLC-ICP MS allowed the separation of the porphyrin-type fraction as well as separation of the remaining species into three distinct fractions. The metal species in the SEC fractions were found to be sufficiently stable to be collected and preconcentrated to allow the development of a bidimensional chromatography SEC-NP-HPLC-ICPMS for the probing of the metal distribution in crude oils in terms of molecular weight and polarity.
Elaine Stephens - One of the best experts on this subject based on the ideXlab platform.
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structure elucidation of arabinoxylan isomers by Normal Phase HPLC maldi tof tof ms ms
Carbohydrate Research, 2007Co-Authors: Sarah L Maslen, Florence Goubet, Alex Adam, Paul Dupree, Elaine StephensAbstract:Normal Phase-high performance liquid chromatography (NP-HPLC) coupled to matrix-assisted laser desorption/ionization-time-of-flight/time-of-flight (MALDI-TOF/TOF) tandem mass spectrometry is evaluated for the detailed structural characterization of various isomers of arabinoxylan (AX) oligosaccharides produced from endo-β-(1→4)-xylanase (endoxylanase) digestion of wheat AX. The fragmentation characteristics of these oligosaccharides upon MALDI-TOF/TOF high-energy collision induced dissociation (CID) were investigated using purified AX oligosaccharide standards labeled at the reducing end with 2-aminobenzoic acid (2-AA). A variety of cross-ring cleavages and ‘elimination’ ions in the fragment ion spectra provided extensive structural information, including Araf substitution patterns along the xylan backbone and comprehensive linkage assignment. The off-line coupling of this MALDI-CID technique to capillary Normal Phase HPLC enabled the separation and identification of isomeric oligosaccharides (DP 4–8) produced by endoxylanase digestion of AX. Furthermore, this technique was used to characterize structurally different isomeric AX oligosaccharides produced by endoxylanase enzymes with different substrate specificities.
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Structure elucidation of arabinoxylan isomers by Normal Phase HPLC-MALDI-TOF/TOF-MS/MS.
Carbohydrate Research, 2006Co-Authors: Sarah L Maslen, Florence Goubet, Alex Adam, Paul Dupree, Elaine StephensAbstract:Normal Phase-high performance liquid chromatography (NP-HPLC) coupled to matrix-assisted laser desorption/ionization-time-of-flight/time-of-flight (MALDI-TOF/TOF) tandem mass spectrometry is evaluated for the detailed structural characterization of various isomers of arabinoxylan (AX) oligosaccharides produced from endo-β-(1→4)-xylanase (endoxylanase) digestion of wheat AX. The fragmentation characteristics of these oligosaccharides upon MALDI-TOF/TOF high-energy collision induced dissociation (CID) were investigated using purified AX oligosaccharide standards labeled at the reducing end with 2-aminobenzoic acid (2-AA). A variety of cross-ring cleavages and ‘elimination’ ions in the fragment ion spectra provided extensive structural information, including Araf substitution patterns along the xylan backbone and comprehensive linkage assignment. The off-line coupling of this MALDI-CID technique to capillary Normal Phase HPLC enabled the separation and identification of isomeric oligosaccharides (DP 4–8) produced by endoxylanase digestion of AX. Furthermore, this technique was used to characterize structurally different isomeric AX oligosaccharides produced by endoxylanase enzymes with different substrate specificities.
Brice Bouyssiere - One of the best experts on this subject based on the ideXlab platform.
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fractionation and speciation of nickel and vanadium in crude oils by size exclusion chromatography icp ms and Normal Phase HPLC icp ms
Journal of Analytical Atomic Spectrometry, 2010Co-Authors: G. Caumette, Brice Bouyssiere, Charles Philippe Lienemann, Isabelle Merdrignac, Ryszard LobinskiAbstract:The coupling of size exclusion chromatography (SEC) and Normal Phase (NP) HPLC using entirely organic mobile Phases (tetrahydrofuran, xylene) with inductively coupled plasma mass spectrometry (ICP MS) were developed and investigated for the molecular distribution of nickel and vanadium in crude oils. The metal species were fractionated by SEC using three columns in series with the increasing porosity (100, 1000 and 100000 A) covering the molecular mass range (in eq. polystyrene) between 300 and 2 × 106 Da. The resolution achieved allowed the discrimination of at least three classes of Ni and V species with varying proportions of the metals as a function of the origin of crude oil, crude oil fraction (asphaltene, maltene) and dilution factor. Normal Phase HPLC-ICP MS allowed the separation of the porphyrin-type fraction as well as separation of the remaining species into three distinct fractions. The metal species in the SEC fractions were found to be sufficiently stable to be collected and preconcentrated to allow the development of a bidimensional chromatography SEC-NP-HPLC-ICPMS for the probing of the metal distribution in crude oils in terms of molecular weight and polarity.
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Fractionation and speciation of nickel and vanadium in crude oils by size exclusion chromatography-ICP MS and Normal Phase HPLC-ICP MS
Journal of Analytical Atomic Spectrometry, 2010Co-Authors: G. Caumette, Brice Bouyssiere, Charles Philippe Lienemann, Isabelle Merdrignac, Ryszard LobinskiAbstract:The coupling of size exclusion chromatography (SEC) and Normal Phase (NP) HPLC using entirely organic mobile Phases (tetrahydrofuran, xylene) with inductively coupled plasma mass spectrometry (ICP MS) were developed and investigated for the molecular distribution of nickel and vanadium in crude oils. The metal species were fractionated by SEC using three columns in series with the increasing porosity (100, 1000 and 100000 A) covering the molecular mass range (in eq. polystyrene) between 300 and 2 [times] 106 Da. The resolution achieved allowed the discrimination of at least three classes of Ni and V species with varying proportions of the metals as a function of the origin of crude oil, crude oil fraction (asphaltene, maltene) and dilution factor. Normal Phase HPLC-ICP MS allowed the separation of the porphyrin-type fraction as well as separation of the remaining species into three distinct fractions. The metal species in the SEC fractions were found to be sufficiently stable to be collected and preconcentrated to allow the development of a bidimensional chromatography SEC-NP-HPLC-ICPMS for the probing of the metal distribution in crude oils in terms of molecular weight and polarity.
Isabelle Merdrignac - One of the best experts on this subject based on the ideXlab platform.
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fractionation and speciation of nickel and vanadium in crude oils by size exclusion chromatography icp ms and Normal Phase HPLC icp ms
Journal of Analytical Atomic Spectrometry, 2010Co-Authors: G. Caumette, Brice Bouyssiere, Charles Philippe Lienemann, Isabelle Merdrignac, Ryszard LobinskiAbstract:The coupling of size exclusion chromatography (SEC) and Normal Phase (NP) HPLC using entirely organic mobile Phases (tetrahydrofuran, xylene) with inductively coupled plasma mass spectrometry (ICP MS) were developed and investigated for the molecular distribution of nickel and vanadium in crude oils. The metal species were fractionated by SEC using three columns in series with the increasing porosity (100, 1000 and 100000 A) covering the molecular mass range (in eq. polystyrene) between 300 and 2 × 106 Da. The resolution achieved allowed the discrimination of at least three classes of Ni and V species with varying proportions of the metals as a function of the origin of crude oil, crude oil fraction (asphaltene, maltene) and dilution factor. Normal Phase HPLC-ICP MS allowed the separation of the porphyrin-type fraction as well as separation of the remaining species into three distinct fractions. The metal species in the SEC fractions were found to be sufficiently stable to be collected and preconcentrated to allow the development of a bidimensional chromatography SEC-NP-HPLC-ICPMS for the probing of the metal distribution in crude oils in terms of molecular weight and polarity.
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Fractionation and speciation of nickel and vanadium in crude oils by size exclusion chromatography-ICP MS and Normal Phase HPLC-ICP MS
Journal of Analytical Atomic Spectrometry, 2010Co-Authors: G. Caumette, Brice Bouyssiere, Charles Philippe Lienemann, Isabelle Merdrignac, Ryszard LobinskiAbstract:The coupling of size exclusion chromatography (SEC) and Normal Phase (NP) HPLC using entirely organic mobile Phases (tetrahydrofuran, xylene) with inductively coupled plasma mass spectrometry (ICP MS) were developed and investigated for the molecular distribution of nickel and vanadium in crude oils. The metal species were fractionated by SEC using three columns in series with the increasing porosity (100, 1000 and 100000 A) covering the molecular mass range (in eq. polystyrene) between 300 and 2 [times] 106 Da. The resolution achieved allowed the discrimination of at least three classes of Ni and V species with varying proportions of the metals as a function of the origin of crude oil, crude oil fraction (asphaltene, maltene) and dilution factor. Normal Phase HPLC-ICP MS allowed the separation of the porphyrin-type fraction as well as separation of the remaining species into three distinct fractions. The metal species in the SEC fractions were found to be sufficiently stable to be collected and preconcentrated to allow the development of a bidimensional chromatography SEC-NP-HPLC-ICPMS for the probing of the metal distribution in crude oils in terms of molecular weight and polarity.
