The Experts below are selected from a list of 303 Experts worldwide ranked by ideXlab platform
Robert J. Hurtubise - One of the best experts on this subject based on the ideXlab platform.
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Solid-Matrix luminescence of heterocyclic aromatic amines in several new sugar-glass systems
Talanta, 2006Co-Authors: Sara E. Hubbard, Robert J. HurtubiseAbstract:Several new sugar glasses were investigated for their potential in Solid-Matrix luminescence. Both Solid-Matrix fluorescence (SMF) and Solid-Matrix phosphorescence (SMP) properties were obtained, and two heterocyclic aromatic amines were employed as model compounds. In addition to glucose glasses, which were investigated previously, fructose, ribose, xylose, galactose, maltose, and glucose with poly(acrylic acid) (PAA) were studied. Detailed experimental conditions were obtained for each sugar-glass system. In addition, NaI was investigated as a heavy-atom salt in the sugar-glass systems to enhance the SMP of the heterocyclic aromatic amines. The SMF intensity was the strongest in maltose and glucose with PAA for 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) and in maltose for 2-amino-9H-pyrido[2,3-b]indole (AalphaC). The largest SMP signals for PhIP with and without NaI were acquired in glucose with PAA. For AalphaC with NaI, the strongest SMP signal was obtained in maltose. Limits of detection were obtained for PhIP in the several sugar-glass systems, and the lowest limit of detection was 0.04pmol/mg of PhIP in maltose with NaI present. An extensive study was carried out using both SMF and SMP to determine if neutral and/or protonated species of PhIP and AalphaC were in the sugar-glass systems. General guidelines such as glass transition temperature and solubility are discussed for selecting a sugar glass as a Solid Matrix.
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Solid-Matrix Luminescence Analysis and Coupling Solid-Matrix Luminescence with Separation Methodology
2004Co-Authors: Robert J. HurtubiseAbstract:In this report, the major results and conclusions of the research over the last two years and five months is considered. The report discusses the mechanistic aspects of oxygen quenching of Solid-Matrix phosphorescence (SMP), mechanistic aspects of moisture quenching of SMP, interactions and methodology to investigate phosphors in glucose glasses, new methods for coating filter paper for Solid-phase microextraction with Solid-Matrix fluorescence (SMF) and SMP detection, mechanistic consideration of the heavy-atom quenching of the SMF and the enhancement of SMP of benzo[a]pyrene-DNA adducts, and new developments in liquid-liquid-liquid microextraction.
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new methodology for the characterization of anti bpde dna adducts and tetrol i 1 with Solid Matrix phosphorescence
Analytica Chimica Acta, 2004Co-Authors: Barry W Smith, Robert J. HurtubiseAbstract:Abstract Novel Solid-Matrix phosphorescence (SMP) methods were developed for the detection and characterization of (±)- anti -benzo[a]pyrene- trans -7,8-dihydrodiol-9,10-epoxide ((±)- anti -BPDE)-DNA adducts and a hydrolysis product of the (±)- anti -BPDE-DNA adducts, tetrol I-1, by using the heavy-atom salts, thallium nitrate and sodium iodide, to enhance the Solid-Matrix phosphorescence. Thallium nitrate was much more effective for enhancing the SMP of the (±)- anti -BPDE-DNA adducts and tetrol I-1. Thus, the results from TlNO 3 were emphasized. The amount of TlNO 3 adsorbed on the Solid Matrix was varied over a wide range, and SMP intensities, lifetimes, and spectra were acquired. Fundamental equations and calculated photophysical parameters were used to interpret the data and characterize the samples. The data indicated that there were two major populations of the (±)- anti -BPDE-DNA adducts and tetrol I-1 adsorbed on the Solid Matrix. Because DNA was adsorbed so strongly to the Solid Matrix, the (±)- anti -BPDE-DNA adducts interacted in a uniform manner with increasing amounts of TlNO 3 . However, tetrol I-1 responded in a more random fashion with the increase in the amount of TlNO 3 . The methods developed can be used to compare the SMP of small molecular-weight metabolites and DNA samples modified at different levels of (±)- anti -BPDE. Also, the methodology can be employed for DNA samples that are adducted with any material that would give measurable SMP.
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New methodology for the characterization of (±)-anti-BPDE-DNA adducts and tetrol I-1 with Solid-Matrix phosphorescence
Analytica Chimica Acta, 2004Co-Authors: Barry W Smith, Robert J. HurtubiseAbstract:Abstract Novel Solid-Matrix phosphorescence (SMP) methods were developed for the detection and characterization of (±)- anti -benzo[a]pyrene- trans -7,8-dihydrodiol-9,10-epoxide ((±)- anti -BPDE)-DNA adducts and a hydrolysis product of the (±)- anti -BPDE-DNA adducts, tetrol I-1, by using the heavy-atom salts, thallium nitrate and sodium iodide, to enhance the Solid-Matrix phosphorescence. Thallium nitrate was much more effective for enhancing the SMP of the (±)- anti -BPDE-DNA adducts and tetrol I-1. Thus, the results from TlNO 3 were emphasized. The amount of TlNO 3 adsorbed on the Solid Matrix was varied over a wide range, and SMP intensities, lifetimes, and spectra were acquired. Fundamental equations and calculated photophysical parameters were used to interpret the data and characterize the samples. The data indicated that there were two major populations of the (±)- anti -BPDE-DNA adducts and tetrol I-1 adsorbed on the Solid Matrix. Because DNA was adsorbed so strongly to the Solid Matrix, the (±)- anti -BPDE-DNA adducts interacted in a uniform manner with increasing amounts of TlNO 3 . However, tetrol I-1 responded in a more random fashion with the increase in the amount of TlNO 3 . The methods developed can be used to compare the SMP of small molecular-weight metabolites and DNA samples modified at different levels of (±)- anti -BPDE. Also, the methodology can be employed for DNA samples that are adducted with any material that would give measurable SMP.
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Characterization of tetrol I-1 and (+/-)-anti-BPDE-DNA adducts with Solid-Matrix fluorescence quenching.
Applied Spectroscopy, 2003Co-Authors: Barry W Smith, Robert J. HurtubiseAbstract:The Solid-Matrix fluorescence (SMF) quenching of (±)-anti-benzo[a]pyrene-trans-7,8-dihydrodiol-9,10-epoxide (BPDE)-DNA adducts and a hydrolysis product of the DNA adducts, tetrol I-1, were investigated by using thallium nitrate and sodium iodide to quench the SMF. Several fluorescence quenching models were evaluated for both (±)-anti-BPDE-DNA adducts and tetrol I-1. The SMF quenching phenomena were quite different with the two salts for the (±)-anti-BPDE-DNA adducts and tetrol I-1. Generally, with thallium nitrate as a quencher, a two-site model with two independent quenching sites was applicable to both the (±)-anti-BPDE-DNA adducts and tetrol I-1 data. However, with sodium iodide, the SMF quenching data for tetrol I-1 were fit to the sphere of action model, but the (±)-anti-BPDE-DNA adducts SMF quenching data were qualitatively related to a BET isotherm. From the SMF quenching data, unique information was acquired for the quasi-intercalated BPDE-DNA adducts and the external form of the BPDE-DNA adducts. In addition, insights were obtained on how the adsorbed salts interacted with the Solid Matrix and with the (±)-anti-BPDE-DNA adducts and tetrol I-1.
Jae Chul Pyun - One of the best experts on this subject based on the ideXlab platform.
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Analysis of benzylpenicillin in milk using MALDI-TOF mass spectrometry with top-down synthesized TiO2 nanowires as the Solid Matrix
Chemosphere, 2015Co-Authors: Jo Il Kim, Jong-min Park, Min Jung Kang, Joo Yoon Noh, Seong-ju Hwang, Jae Chul PyunAbstract:In this work, the wet-corrosion process for the synthesis of titanium oxide (TiO2) nanowires in the anatase phase was optimized as the Solid Matrix in MALDI-TOF mass spectrometry, and the Solid Matrix of the TiO2 nanowires was applied to the detection of antibiotics in a daily milk sample. The influence of the alkali concentration and the heat treatment temperature on the crystal structure of the TiO2 nanowires was investigated. The ionization activity of the TiO2 nanowires was estimated for each synthetic condition using amino acids as model analytes with low molecular weights. For the detection of antibiotics in milk, benzylpenicillin was spiked in daily milk samples, and MALDI-TOF mass spectrometry with the TiO2 nanowires was demonstrated to detect the benzylpenicillin at the cut-off concentration of the EU directive.
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Nylon nanoweb with TiO2 nanoparticles as a Solid Matrix for Matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry
Rapid communications in mass spectrometry : RCM, 2014Co-Authors: Jo Il Kim, Jong-min Park, Min Jung Kang, Joo Yoon Noh, Su-yeol Ryu, Seung-yeop Kwak, Jae Chul PyunAbstract:RATIONALE The Solid matrices used for Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS) enable the analysis of small molecules by preventing fragmentations of organic Matrix molecules in the low mass-to-charge ratio (m/z) range. In this work, a nylon nanoweb with TiO(2) particles was developed as a Solid Matrix for MALDI-TOFMS to improve the low intensities of mass peaks, narrow detection ranges and low signal-to-noise levels. METHODS The nylon nanoweb with TiO(2) particles was prepared by simultaneously electrospinning a nylon nanoweb and electrospraying TiO(2) nanoparticles measuring 25 nm in diameter to form TiO(2) spheres 300 nm in diameter. RESULTS MS of multiple analytes was demonstrated in the low molecular weight range using eight amino acids. Additionally, leucine-enkephalin (555.6 g/mol) and cyclic citrullinated peptide (1668 g/mol) were used as model analytes to test the feasibility of a nylon nanoweb containing TiO(2) particles as a Solid Matrix for MALDI-TOFMS. CONCLUSIONS The nylon nanoweb with TiO(2) particles can be applied for the detection of volatile small molecule analytes in the m/z ratio range of small molecules.
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Top-down synthesized TiO2 nanowires as a Solid Matrix for surface-assisted laser desorption/ionization time-of-flight (SALDI-TOF) mass spectrometry
Analytica chimica acta, 2014Co-Authors: Jo Il Kim, Jong-min Park, Seung-ju Hwang, Min Jung Kang, Jae Chul PyunAbstract:Top-down synthesized TiO2 nanowires are presented as an ideal Solid Matrix to analyze small biomolecules at a m/z of less than 500. The TiO2 nanowires were synthesized as arrays using a modified hydrothermal process directly on the surface of a Ti plate. Finally, the feasibility of the TiO2 nanowires in the anatase phase as a Solid Matrix. The crystal and electronic structures of the top-down TiO2 nanowires were analyzed at each step of the hydrothermal process, and the optimal TiO2 nanowires were identified by checking their performance toward the ionization of analytes in surface-assisted laser desorption/ionization time-of-flight (SALDI-TOF) mass spectrometry. Finally, the feasibility of the TiO2 nanowires in the anatase phase as a Solid Matrix for SALDI-TOF mass spectrometry was demonstrated using eight types of amino acids and peptides as model analytes.
Jo Il Kim - One of the best experts on this subject based on the ideXlab platform.
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Analysis of benzylpenicillin in milk using MALDI-TOF mass spectrometry with top-down synthesized TiO2 nanowires as the Solid Matrix
Chemosphere, 2015Co-Authors: Jo Il Kim, Jong-min Park, Min Jung Kang, Joo Yoon Noh, Seong-ju Hwang, Jae Chul PyunAbstract:In this work, the wet-corrosion process for the synthesis of titanium oxide (TiO2) nanowires in the anatase phase was optimized as the Solid Matrix in MALDI-TOF mass spectrometry, and the Solid Matrix of the TiO2 nanowires was applied to the detection of antibiotics in a daily milk sample. The influence of the alkali concentration and the heat treatment temperature on the crystal structure of the TiO2 nanowires was investigated. The ionization activity of the TiO2 nanowires was estimated for each synthetic condition using amino acids as model analytes with low molecular weights. For the detection of antibiotics in milk, benzylpenicillin was spiked in daily milk samples, and MALDI-TOF mass spectrometry with the TiO2 nanowires was demonstrated to detect the benzylpenicillin at the cut-off concentration of the EU directive.
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Nylon nanoweb with TiO2 nanoparticles as a Solid Matrix for Matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry
Rapid communications in mass spectrometry : RCM, 2014Co-Authors: Jo Il Kim, Jong-min Park, Min Jung Kang, Joo Yoon Noh, Su-yeol Ryu, Seung-yeop Kwak, Jae Chul PyunAbstract:RATIONALE The Solid matrices used for Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS) enable the analysis of small molecules by preventing fragmentations of organic Matrix molecules in the low mass-to-charge ratio (m/z) range. In this work, a nylon nanoweb with TiO(2) particles was developed as a Solid Matrix for MALDI-TOFMS to improve the low intensities of mass peaks, narrow detection ranges and low signal-to-noise levels. METHODS The nylon nanoweb with TiO(2) particles was prepared by simultaneously electrospinning a nylon nanoweb and electrospraying TiO(2) nanoparticles measuring 25 nm in diameter to form TiO(2) spheres 300 nm in diameter. RESULTS MS of multiple analytes was demonstrated in the low molecular weight range using eight amino acids. Additionally, leucine-enkephalin (555.6 g/mol) and cyclic citrullinated peptide (1668 g/mol) were used as model analytes to test the feasibility of a nylon nanoweb containing TiO(2) particles as a Solid Matrix for MALDI-TOFMS. CONCLUSIONS The nylon nanoweb with TiO(2) particles can be applied for the detection of volatile small molecule analytes in the m/z ratio range of small molecules.
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Top-down synthesized TiO2 nanowires as a Solid Matrix for surface-assisted laser desorption/ionization time-of-flight (SALDI-TOF) mass spectrometry
Analytica chimica acta, 2014Co-Authors: Jo Il Kim, Jong-min Park, Seung-ju Hwang, Min Jung Kang, Jae Chul PyunAbstract:Top-down synthesized TiO2 nanowires are presented as an ideal Solid Matrix to analyze small biomolecules at a m/z of less than 500. The TiO2 nanowires were synthesized as arrays using a modified hydrothermal process directly on the surface of a Ti plate. Finally, the feasibility of the TiO2 nanowires in the anatase phase as a Solid Matrix. The crystal and electronic structures of the top-down TiO2 nanowires were analyzed at each step of the hydrothermal process, and the optimal TiO2 nanowires were identified by checking their performance toward the ionization of analytes in surface-assisted laser desorption/ionization time-of-flight (SALDI-TOF) mass spectrometry. Finally, the feasibility of the TiO2 nanowires in the anatase phase as a Solid Matrix for SALDI-TOF mass spectrometry was demonstrated using eight types of amino acids and peptides as model analytes.
Jong-min Park - One of the best experts on this subject based on the ideXlab platform.
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Analysis of benzylpenicillin in milk using MALDI-TOF mass spectrometry with top-down synthesized TiO2 nanowires as the Solid Matrix
Chemosphere, 2015Co-Authors: Jo Il Kim, Jong-min Park, Min Jung Kang, Joo Yoon Noh, Seong-ju Hwang, Jae Chul PyunAbstract:In this work, the wet-corrosion process for the synthesis of titanium oxide (TiO2) nanowires in the anatase phase was optimized as the Solid Matrix in MALDI-TOF mass spectrometry, and the Solid Matrix of the TiO2 nanowires was applied to the detection of antibiotics in a daily milk sample. The influence of the alkali concentration and the heat treatment temperature on the crystal structure of the TiO2 nanowires was investigated. The ionization activity of the TiO2 nanowires was estimated for each synthetic condition using amino acids as model analytes with low molecular weights. For the detection of antibiotics in milk, benzylpenicillin was spiked in daily milk samples, and MALDI-TOF mass spectrometry with the TiO2 nanowires was demonstrated to detect the benzylpenicillin at the cut-off concentration of the EU directive.
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Nylon nanoweb with TiO2 nanoparticles as a Solid Matrix for Matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry
Rapid communications in mass spectrometry : RCM, 2014Co-Authors: Jo Il Kim, Jong-min Park, Min Jung Kang, Joo Yoon Noh, Su-yeol Ryu, Seung-yeop Kwak, Jae Chul PyunAbstract:RATIONALE The Solid matrices used for Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS) enable the analysis of small molecules by preventing fragmentations of organic Matrix molecules in the low mass-to-charge ratio (m/z) range. In this work, a nylon nanoweb with TiO(2) particles was developed as a Solid Matrix for MALDI-TOFMS to improve the low intensities of mass peaks, narrow detection ranges and low signal-to-noise levels. METHODS The nylon nanoweb with TiO(2) particles was prepared by simultaneously electrospinning a nylon nanoweb and electrospraying TiO(2) nanoparticles measuring 25 nm in diameter to form TiO(2) spheres 300 nm in diameter. RESULTS MS of multiple analytes was demonstrated in the low molecular weight range using eight amino acids. Additionally, leucine-enkephalin (555.6 g/mol) and cyclic citrullinated peptide (1668 g/mol) were used as model analytes to test the feasibility of a nylon nanoweb containing TiO(2) particles as a Solid Matrix for MALDI-TOFMS. CONCLUSIONS The nylon nanoweb with TiO(2) particles can be applied for the detection of volatile small molecule analytes in the m/z ratio range of small molecules.
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Top-down synthesized TiO2 nanowires as a Solid Matrix for surface-assisted laser desorption/ionization time-of-flight (SALDI-TOF) mass spectrometry
Analytica chimica acta, 2014Co-Authors: Jo Il Kim, Jong-min Park, Seung-ju Hwang, Min Jung Kang, Jae Chul PyunAbstract:Top-down synthesized TiO2 nanowires are presented as an ideal Solid Matrix to analyze small biomolecules at a m/z of less than 500. The TiO2 nanowires were synthesized as arrays using a modified hydrothermal process directly on the surface of a Ti plate. Finally, the feasibility of the TiO2 nanowires in the anatase phase as a Solid Matrix. The crystal and electronic structures of the top-down TiO2 nanowires were analyzed at each step of the hydrothermal process, and the optimal TiO2 nanowires were identified by checking their performance toward the ionization of analytes in surface-assisted laser desorption/ionization time-of-flight (SALDI-TOF) mass spectrometry. Finally, the feasibility of the TiO2 nanowires in the anatase phase as a Solid Matrix for SALDI-TOF mass spectrometry was demonstrated using eight types of amino acids and peptides as model analytes.
Min Jung Kang - One of the best experts on this subject based on the ideXlab platform.
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Analysis of benzylpenicillin in milk using MALDI-TOF mass spectrometry with top-down synthesized TiO2 nanowires as the Solid Matrix
Chemosphere, 2015Co-Authors: Jo Il Kim, Jong-min Park, Min Jung Kang, Joo Yoon Noh, Seong-ju Hwang, Jae Chul PyunAbstract:In this work, the wet-corrosion process for the synthesis of titanium oxide (TiO2) nanowires in the anatase phase was optimized as the Solid Matrix in MALDI-TOF mass spectrometry, and the Solid Matrix of the TiO2 nanowires was applied to the detection of antibiotics in a daily milk sample. The influence of the alkali concentration and the heat treatment temperature on the crystal structure of the TiO2 nanowires was investigated. The ionization activity of the TiO2 nanowires was estimated for each synthetic condition using amino acids as model analytes with low molecular weights. For the detection of antibiotics in milk, benzylpenicillin was spiked in daily milk samples, and MALDI-TOF mass spectrometry with the TiO2 nanowires was demonstrated to detect the benzylpenicillin at the cut-off concentration of the EU directive.
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Nylon nanoweb with TiO2 nanoparticles as a Solid Matrix for Matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry
Rapid communications in mass spectrometry : RCM, 2014Co-Authors: Jo Il Kim, Jong-min Park, Min Jung Kang, Joo Yoon Noh, Su-yeol Ryu, Seung-yeop Kwak, Jae Chul PyunAbstract:RATIONALE The Solid matrices used for Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS) enable the analysis of small molecules by preventing fragmentations of organic Matrix molecules in the low mass-to-charge ratio (m/z) range. In this work, a nylon nanoweb with TiO(2) particles was developed as a Solid Matrix for MALDI-TOFMS to improve the low intensities of mass peaks, narrow detection ranges and low signal-to-noise levels. METHODS The nylon nanoweb with TiO(2) particles was prepared by simultaneously electrospinning a nylon nanoweb and electrospraying TiO(2) nanoparticles measuring 25 nm in diameter to form TiO(2) spheres 300 nm in diameter. RESULTS MS of multiple analytes was demonstrated in the low molecular weight range using eight amino acids. Additionally, leucine-enkephalin (555.6 g/mol) and cyclic citrullinated peptide (1668 g/mol) were used as model analytes to test the feasibility of a nylon nanoweb containing TiO(2) particles as a Solid Matrix for MALDI-TOFMS. CONCLUSIONS The nylon nanoweb with TiO(2) particles can be applied for the detection of volatile small molecule analytes in the m/z ratio range of small molecules.
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Top-down synthesized TiO2 nanowires as a Solid Matrix for surface-assisted laser desorption/ionization time-of-flight (SALDI-TOF) mass spectrometry
Analytica chimica acta, 2014Co-Authors: Jo Il Kim, Jong-min Park, Seung-ju Hwang, Min Jung Kang, Jae Chul PyunAbstract:Top-down synthesized TiO2 nanowires are presented as an ideal Solid Matrix to analyze small biomolecules at a m/z of less than 500. The TiO2 nanowires were synthesized as arrays using a modified hydrothermal process directly on the surface of a Ti plate. Finally, the feasibility of the TiO2 nanowires in the anatase phase as a Solid Matrix. The crystal and electronic structures of the top-down TiO2 nanowires were analyzed at each step of the hydrothermal process, and the optimal TiO2 nanowires were identified by checking their performance toward the ionization of analytes in surface-assisted laser desorption/ionization time-of-flight (SALDI-TOF) mass spectrometry. Finally, the feasibility of the TiO2 nanowires in the anatase phase as a Solid Matrix for SALDI-TOF mass spectrometry was demonstrated using eight types of amino acids and peptides as model analytes.
