The Experts below are selected from a list of 15417 Experts worldwide ranked by ideXlab platform
Ana Ruaibarz - One of the best experts on this subject based on the ideXlab platform.
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characterization of iron oxide nanoparticles by means of single particle icp mass spectrometry sp icp ms chemical versus physical resolution to overcome spectral overlap
Journal of Analytical Atomic Spectrometry, 2020Co-Authors: Frank Vanhaecke, Ana Ruaibarz, Eduardo Boleafernandez, Guillermo Pozo, Xochitl Dominguezbenetton, Kristof TirezAbstract:As a result of their unique physical, chemical and/or biological properties, the use of engineered nanoparticles (ENPs) is growing very rapidly. Iron oxide nanoparticles (IONPs) are of particular interest owing to their magnetic properties, and thus the development of suitable methods for their characterization is essential. Inductively coupled plasma-mass spectrometry (ICP-MS) operated in single-particle (SP) Mode provides different types of relevant information, such as size distribution and particle number and mass concentrations. However, the use of SP-ICP-MS becomes less straightforward when the analyte signal is subject to spectral overlap. In the case of IONPs, characterization by means of SP-ICP-MS is hindered by the occurrence of ArO+ polyatomic ions with the same nominal mass-to-charge (m/z) ratio as the most abundant Fe isotope. In this work, different approaches relying on either chemical or physical (mass) resolution, to avoid this spectral interference otherwise jeopardizing accurate results, were assessed. In the case of chemical resolution, the performance of on-mass and mass-shift approaches was evaluated using different types of quadrupole-based ICP-MS instrumentation, including single-quadrupole (SQ) and tandem ICP-MS (ICP-MS/MS) units. Physical resolution was accomplished using a new generation of sector field (SF) ICP-MS instrumentation, capable of dealing with transient signals of extremely short duration (10–100 μs dwell time), even when operated at higher mass resolution (pseudo-resolution Mode). Based on the figures-of-merit obtained for the different approaches evaluated, an on-mass approach using NH3 as the reaction gas in SQ-ICP-MS, an on-mass approach using H2 as the collision/reaction gas in ICP-MS/MS and pseudo-medium resolution in SF-ICP-MS were found to be the best-suited approaches for fast interference-free monitoring of the ion signals generated by IONPs in SP Mode. While the use of chemical (H2/on-mass) and physical (pseudo-medium) resolutions also provided accurate and precise results for custom-made Fe3O4 (magnetite) NPs of ≈50 nm, the use of NH3 was less successful, as it leads to an extension of the SP pulse profile and a lower signal-to-background ratio. Finally, SF-ICP-MS operated in pseudo-medium resolution Mode was used for the characterization of Fe3O4 NPs synthesized electrochemically (batch and Continuous Operation Mode).
Kristof Tirez - One of the best experts on this subject based on the ideXlab platform.
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characterization of iron oxide nanoparticles by means of single particle icp mass spectrometry sp icp ms chemical versus physical resolution to overcome spectral overlap
Journal of Analytical Atomic Spectrometry, 2020Co-Authors: Frank Vanhaecke, Ana Ruaibarz, Eduardo Boleafernandez, Guillermo Pozo, Xochitl Dominguezbenetton, Kristof TirezAbstract:As a result of their unique physical, chemical and/or biological properties, the use of engineered nanoparticles (ENPs) is growing very rapidly. Iron oxide nanoparticles (IONPs) are of particular interest owing to their magnetic properties, and thus the development of suitable methods for their characterization is essential. Inductively coupled plasma-mass spectrometry (ICP-MS) operated in single-particle (SP) Mode provides different types of relevant information, such as size distribution and particle number and mass concentrations. However, the use of SP-ICP-MS becomes less straightforward when the analyte signal is subject to spectral overlap. In the case of IONPs, characterization by means of SP-ICP-MS is hindered by the occurrence of ArO+ polyatomic ions with the same nominal mass-to-charge (m/z) ratio as the most abundant Fe isotope. In this work, different approaches relying on either chemical or physical (mass) resolution, to avoid this spectral interference otherwise jeopardizing accurate results, were assessed. In the case of chemical resolution, the performance of on-mass and mass-shift approaches was evaluated using different types of quadrupole-based ICP-MS instrumentation, including single-quadrupole (SQ) and tandem ICP-MS (ICP-MS/MS) units. Physical resolution was accomplished using a new generation of sector field (SF) ICP-MS instrumentation, capable of dealing with transient signals of extremely short duration (10–100 μs dwell time), even when operated at higher mass resolution (pseudo-resolution Mode). Based on the figures-of-merit obtained for the different approaches evaluated, an on-mass approach using NH3 as the reaction gas in SQ-ICP-MS, an on-mass approach using H2 as the collision/reaction gas in ICP-MS/MS and pseudo-medium resolution in SF-ICP-MS were found to be the best-suited approaches for fast interference-free monitoring of the ion signals generated by IONPs in SP Mode. While the use of chemical (H2/on-mass) and physical (pseudo-medium) resolutions also provided accurate and precise results for custom-made Fe3O4 (magnetite) NPs of ≈50 nm, the use of NH3 was less successful, as it leads to an extension of the SP pulse profile and a lower signal-to-background ratio. Finally, SF-ICP-MS operated in pseudo-medium resolution Mode was used for the characterization of Fe3O4 NPs synthesized electrochemically (batch and Continuous Operation Mode).
Lin Li - One of the best experts on this subject based on the ideXlab platform.
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removal of airborne microorganisms emitted from a wastewater treatment oxidation ditch by adsorption on activated carbon
Journal of Environmental Sciences-china, 2011Co-Authors: Lin LiAbstract:Bioaerosol emissions from wastewater and wastewater treatment processes are a significant subgroup of atmospheric aerosols. Most previous work has focused on the evaluation of their biological risks. In this study, however, the adsorption method was applied to reduce airborne microorganisms generated from a pilot scale wastewater treatment facility with oxidation ditch. Results showed adsorption on granule activated carbon (GAC) was an efficient method for the purification of airborne microorganisms. The GAC itself had a maximum adsorption capacity of 2217 CFU/g for airborne bacteria and 225 CFU/g for fungi with a flow rate of 1.50 m(3)/hr. Over 85% of airborne bacteria and fungi emitted from the oxidation ditch were adsorbed within 80 hr of Continuous Operation Mode. Most of them had a particle size of 0.65-4.7 mu m. Those airborne microorganisms with small particle size were apt to be adsorbed. The SEM/EDAX, BET and Boehm's titration methods were applied to analyse the physicochemical characteristics of the GAC. Relationships between GAG surface characteristics and its adsorption performance demonstrated that porous structure, large surface area, and hydrophobicity rendered GAG an effective absorber of airborne microorganisms. Two regenerate methods, ultraviolet irradiation and high pressure vapor, were compared for the regeneration of used activated carbon. High pressure vapor was an effective technique as it totally destroyed the microorganisms adhered to the activated carbon. Microscopic observation was also carried out to investigate original and used adsorbents.
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removal of airborne microorganisms emitted from a wastewater treatment oxidation ditch by adsorption on activated carbon
Journal of Environmental Sciences-china, 2011Co-Authors: Lin LiAbstract:Bioaerosol emissions from wastewater and wastewater treatment processes are a significant subgroup of atmospheric aerosols. Most previous work has focused on the evaluation of their biological risks. In this study, however, the adsorption method was applied to reduce airborne microorganisms generated from a pilot scale wastewater treatment facility with oxidation ditch. Results showed adsorption on granule activated carbon (GAC) was an efficient method for the purification of airborne microorganisms. The GAC itself had a maximum adsorption capacity of 2217 CFU/g for airborne bacteria and 225 CFU/g for fungi with a flow rate of 1.50 m(3)/hr. Over 85% of airborne bacteria and fungi emitted from the oxidation ditch were adsorbed within 80 hr of Continuous Operation Mode. Most of them had a particle size of 0.65-4.7 mu m. Those airborne microorganisms with small particle size were apt to be adsorbed. The SEM/EDAX, BET and Boehm's titration methods were applied to analyse the physicochemical characteristics of the GAC. Relationships between GAG surface characteristics and its adsorption performance demonstrated that porous structure, large surface area, and hydrophobicity rendered GAG an effective absorber of airborne microorganisms. Two regenerate methods, ultraviolet irradiation and high pressure vapor, were compared for the regeneration of used activated carbon. High pressure vapor was an effective technique as it totally destroyed the microorganisms adhered to the activated carbon. Microscopic observation was also carried out to investigate original and used adsorbents.
Xochitl Dominguezbenetton - One of the best experts on this subject based on the ideXlab platform.
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characterization of iron oxide nanoparticles by means of single particle icp mass spectrometry sp icp ms chemical versus physical resolution to overcome spectral overlap
Journal of Analytical Atomic Spectrometry, 2020Co-Authors: Frank Vanhaecke, Ana Ruaibarz, Eduardo Boleafernandez, Guillermo Pozo, Xochitl Dominguezbenetton, Kristof TirezAbstract:As a result of their unique physical, chemical and/or biological properties, the use of engineered nanoparticles (ENPs) is growing very rapidly. Iron oxide nanoparticles (IONPs) are of particular interest owing to their magnetic properties, and thus the development of suitable methods for their characterization is essential. Inductively coupled plasma-mass spectrometry (ICP-MS) operated in single-particle (SP) Mode provides different types of relevant information, such as size distribution and particle number and mass concentrations. However, the use of SP-ICP-MS becomes less straightforward when the analyte signal is subject to spectral overlap. In the case of IONPs, characterization by means of SP-ICP-MS is hindered by the occurrence of ArO+ polyatomic ions with the same nominal mass-to-charge (m/z) ratio as the most abundant Fe isotope. In this work, different approaches relying on either chemical or physical (mass) resolution, to avoid this spectral interference otherwise jeopardizing accurate results, were assessed. In the case of chemical resolution, the performance of on-mass and mass-shift approaches was evaluated using different types of quadrupole-based ICP-MS instrumentation, including single-quadrupole (SQ) and tandem ICP-MS (ICP-MS/MS) units. Physical resolution was accomplished using a new generation of sector field (SF) ICP-MS instrumentation, capable of dealing with transient signals of extremely short duration (10–100 μs dwell time), even when operated at higher mass resolution (pseudo-resolution Mode). Based on the figures-of-merit obtained for the different approaches evaluated, an on-mass approach using NH3 as the reaction gas in SQ-ICP-MS, an on-mass approach using H2 as the collision/reaction gas in ICP-MS/MS and pseudo-medium resolution in SF-ICP-MS were found to be the best-suited approaches for fast interference-free monitoring of the ion signals generated by IONPs in SP Mode. While the use of chemical (H2/on-mass) and physical (pseudo-medium) resolutions also provided accurate and precise results for custom-made Fe3O4 (magnetite) NPs of ≈50 nm, the use of NH3 was less successful, as it leads to an extension of the SP pulse profile and a lower signal-to-background ratio. Finally, SF-ICP-MS operated in pseudo-medium resolution Mode was used for the characterization of Fe3O4 NPs synthesized electrochemically (batch and Continuous Operation Mode).
Guillermo Pozo - One of the best experts on this subject based on the ideXlab platform.
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characterization of iron oxide nanoparticles by means of single particle icp mass spectrometry sp icp ms chemical versus physical resolution to overcome spectral overlap
Journal of Analytical Atomic Spectrometry, 2020Co-Authors: Frank Vanhaecke, Ana Ruaibarz, Eduardo Boleafernandez, Guillermo Pozo, Xochitl Dominguezbenetton, Kristof TirezAbstract:As a result of their unique physical, chemical and/or biological properties, the use of engineered nanoparticles (ENPs) is growing very rapidly. Iron oxide nanoparticles (IONPs) are of particular interest owing to their magnetic properties, and thus the development of suitable methods for their characterization is essential. Inductively coupled plasma-mass spectrometry (ICP-MS) operated in single-particle (SP) Mode provides different types of relevant information, such as size distribution and particle number and mass concentrations. However, the use of SP-ICP-MS becomes less straightforward when the analyte signal is subject to spectral overlap. In the case of IONPs, characterization by means of SP-ICP-MS is hindered by the occurrence of ArO+ polyatomic ions with the same nominal mass-to-charge (m/z) ratio as the most abundant Fe isotope. In this work, different approaches relying on either chemical or physical (mass) resolution, to avoid this spectral interference otherwise jeopardizing accurate results, were assessed. In the case of chemical resolution, the performance of on-mass and mass-shift approaches was evaluated using different types of quadrupole-based ICP-MS instrumentation, including single-quadrupole (SQ) and tandem ICP-MS (ICP-MS/MS) units. Physical resolution was accomplished using a new generation of sector field (SF) ICP-MS instrumentation, capable of dealing with transient signals of extremely short duration (10–100 μs dwell time), even when operated at higher mass resolution (pseudo-resolution Mode). Based on the figures-of-merit obtained for the different approaches evaluated, an on-mass approach using NH3 as the reaction gas in SQ-ICP-MS, an on-mass approach using H2 as the collision/reaction gas in ICP-MS/MS and pseudo-medium resolution in SF-ICP-MS were found to be the best-suited approaches for fast interference-free monitoring of the ion signals generated by IONPs in SP Mode. While the use of chemical (H2/on-mass) and physical (pseudo-medium) resolutions also provided accurate and precise results for custom-made Fe3O4 (magnetite) NPs of ≈50 nm, the use of NH3 was less successful, as it leads to an extension of the SP pulse profile and a lower signal-to-background ratio. Finally, SF-ICP-MS operated in pseudo-medium resolution Mode was used for the characterization of Fe3O4 NPs synthesized electrochemically (batch and Continuous Operation Mode).