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Sugiyama T, Minami M, Uchimura T. Using Resonance-Enhanced Multiphoton Ionization Time-of-Flight Mass Spectrometry to Evaluate the Movement of a Constituent in a Multiple Emulsion. ACS OMEGA 2022; 7:2099-2104. [PMID: 35071898 PMCID: PMC8772314 DOI: 10.1021/acsomega.1c05599] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Accepted: 12/24/2021] [Indexed: 06/14/2023]
Abstract
Herein, we propose a method for evaluating the movement of a constituent in a multiple emulsion while maintaining its original dispersed condition. In this study, an oil-in-water-in-oil (O1/W/O2) emulsion was prepared using a two-step emulsification method with styrene as an analyte species in the inner phase (O1). The emulsion was measured using resonance-enhanced multiphoton ionization time-of-flight mass spectrometry without pretreatment such as centrifugation. From a series of obtained mass spectra, a time profile for the peak areas arising from styrene was constructed. When the emulsion was measured immediately following preparation, a time profile composed of a base, positive, and negative signals confirmed the presence of styrene in the O2, O1, and W phases, respectively. Moreover, while a small amount of styrene was present in the inner O1 phase, almost all of the styrene was found in the outer O2 phase. Furthermore, the results of the obtained time profile were converted into a box plot, and a method for the selection of the base, positive, and negative signals was tentatively determined. Then, the movement of styrene among the phases could be evaluated using the time courses of these signals; the time constant of the movement of styrene from an O1/W droplet to the O2 phase was calculated to be 0.8 h.
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Affiliation(s)
- Tomonobu Sugiyama
- Department
of Materials Science and Engineering, Graduate School of Engineering, University of Fukui, 3-9-1 Bunkyo, Fukui 910-8507, Japan
| | - Minori Minami
- Department
of Materials Science and Biotechnology, School of Engineering, University of Fukui, 3-9-1 Bunkyo, Fukui 910-8507, Japan
| | - Tomohiro Uchimura
- Department
of Materials Science and Engineering, Graduate School of Engineering, University of Fukui, 3-9-1 Bunkyo, Fukui 910-8507, Japan
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IWATA M, UCHIMURA T. Resonance-enhanced Multiphoton Ionization Time-of-Flight Mass Spectrometry for Evaluating Emulsion Inversion via Temperature Change. ANAL SCI 2019; 35:1361-1365. [DOI: 10.2116/analsci.19p272] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- Masafumi IWATA
- Department of Materials Science and Engineering, Graduate School of Engineering, University of Fukui
| | - Tomohiro UCHIMURA
- Department of Materials Science and Engineering, Graduate School of Engineering, University of Fukui
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Takezawa H, Iwata M, Ueyama T, Uchimura T. Using Resonance-Enhanced Multiphoton Ionization Time-of-Flight Mass Spectrometry to Quantitatively Analyze the Creaming of an Emulsion. ACS OMEGA 2019; 4:20362-20366. [PMID: 31815240 PMCID: PMC6894152 DOI: 10.1021/acsomega.9b02930] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Accepted: 11/04/2019] [Indexed: 06/10/2023]
Abstract
In this study, we used a quantitative analytical method to indicate creaming behavior in an emulsion. An oil-in-water emulsion was directly measured by resonance-enhanced multiphoton ionization time-of-flight mass spectrometry, and the time profiles of the peak areas of an oil component, styrene, were obtained at heights of 1, 2, and 3 cm from the bottom of a sample that had a height of 4 cm. All time profiles roughly indicated that the signal intensity increased once, then decreased, and finally settled. Moreover, we proposed a fitting equation for the time profiles by subtracting two sigmoid functions, whereby the degree of the signal increases at the initial stage, the degree of the signal decreases after the increase, and the times for continuing the higher signal intensities were all longer as the monitoring positions were raised. This method would surely provide useful information about emulsions that undergo creaming behavior.
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Shinoda R, Uchimura T. Evaluating the Creaming of an Emulsion via Mass Spectrometry and UV-Vis Spectrophotometry. ACS OMEGA 2018; 3:13752-13756. [PMID: 31458075 PMCID: PMC6644440 DOI: 10.1021/acsomega.8b02283] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Accepted: 10/11/2018] [Indexed: 06/10/2023]
Abstract
The creaming behavior of a turbid oil-in-water emulsion was observed via the processes of multiphoton ionization time-of-flight mass spectrometry (MPI-TOFMS) and ultraviolet-visible spectrophotometry (UV-vis), and the results were compared. The transmittance measurement by UV-vis showed that the turbidity of the toluene emulsion was decreased with time. However, non-negligible errors are common in the measurement of a sample with high turbidity. The online measurement by MPI-TOFMS detected many spikes in the time profile, which revealed the existence of toluene droplets in the emulsion. A smooth time profile suggested that the signal intensity had initially increased, and then decreased with time; the initial concentration of toluene was 3 g/L, which had decreased by half after 60 min. The signal behavior obtained using MPI-TOFMS differed only slightly from that obtained using UV-vis. Since a change in turbidity is not the same as a change in the local concentration of an oil component, MPI-TOFMS is useful for the analysis of a turbid emulsion and offers additional information concerning the creaming phenomenon of an emulsion.
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Development of Multiphoton Ionization Time-of-Flight Mass Spectrometry for the Detection of Small Emulsion Droplets. APPLIED SCIENCES-BASEL 2018. [DOI: 10.3390/app8030413] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
A system for measuring small oil droplets in an oil-in-water (O/W) emulsion was developed using multiphoton ionization time-of-flight mass spectrometry. In the present study, a capillary column with an inner diameter of 15 µm was used for sample introduction. Moreover, a compact microscopic system was constructed for observing an emulsion flowing through a capillary column. As a result, the length for sample introduction was shortened, which is preferable for the direct evaluation of an emulsion. Using this system, the minimum diameter of a detectable toluene droplet in an O/W emulsion was decreased to 1.7 µm. The present system could be used to evaluate the local microenvironment and stability of an emulsion.
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Yamamoto H, Ishigami H, Uchimura T. Online Monitoring of a Styrene Monomer and a Dimer in an Emulsion via Laser Ionization Time-of-Flight Mass Spectrometry. ANAL SCI 2018; 33:731-733. [PMID: 28603195 DOI: 10.2116/analsci.33.731] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Laser ionization time-of-flight mass spectrometry was applied to the online monitoring of a styrene monomer and dimer in an emulsion. During the measurement of a styrene monomer oil-in-water emulsion for this study, a styrene dimer, 1,3-diphenylpropane, was dropped into the emulsion. As a result, signal spikes from both analytes occurred simultaneously, which suggested that either the dimer had moved to the monomer droplets or that the monomer and dimer droplets had aggregated. We concluded that this method could be useful for the direct monitoring of monomers and oligomers in the early stages of emulsion polymerization.
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Affiliation(s)
- Hikaru Yamamoto
- Department of Materials Science and Engineering, Graduate School of Engineering, University of Fukui
| | - Hidaka Ishigami
- Department of Materials Science and Engineering, Graduate School of Engineering, University of Fukui
| | - Tomohiro Uchimura
- Department of Materials Science and Engineering, Graduate School of Engineering, University of Fukui
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Shimo Y, Uchimura T. Time-Profile Measurement of an Emulsion Using Multiphoton Ionization Time-of-Flight Mass Spectrometry in Combination with a Microscope. ANAL SCI 2018; 32:1059-1063. [PMID: 27725604 DOI: 10.2116/analsci.32.1059] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Multiphoton ionization time-of-flight mass spectrometry was applied to the measurement of an oil-in-water emulsion that contained toluene as a dispersed phase. Before the measurement, the sample was sufficiently creamed, and then stirred for a short period of time for dispersion. As a result, several intense spikes appeared on the time profile constructed from the peak area for toluene. In the present study, an optical microscope was used to observe the capillary column for sample introduction, and small toluene droplets along with their aggregates were found in the images of the emulsion flowing through the capillary. The aggregates produced intense spikes comprised of multiple plots, which could be easily marked by applying a moving median filter. In the present study, droplets with minimum diameters as small as 2.9 μm, which corresponds to 13 fL, could be calculated as detectable spikes.
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Affiliation(s)
- Yosuke Shimo
- Department of Materials Science and Engineering, Graduate School of Engineering, University of Fukui
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Miyagawa T, Shimizu S, Miura A, Fukuyama A, Uchimura T. Rapid Evaluation of the Bioremediation of Fuel Oil in Soil by Gas Chromatography–Laser Ionization Time-of-Flight Mass Spectrometry. ANAL LETT 2017. [DOI: 10.1080/00032719.2017.1319378] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- Tomomi Miyagawa
- Department of Materials Science and Engineering, Graduate School of Engineering, University of Fukui, Fukui, Japan
| | - Shiho Shimizu
- Department of Science and Mathematics Education, Faculty of Education, University of Fukui, Fukui, Japan
| | - Asa Miura
- Department of Science and Mathematics Education, Faculty of Education, University of Fukui, Fukui, Japan
| | - Atsuko Fukuyama
- Headquarters for Innovative Society-Academia Cooperation, University of Fukui, Fukui, Japan
| | - Tomohiro Uchimura
- Department of Materials Science and Engineering, Graduate School of Engineering, University of Fukui, Fukui, Japan
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FUJII T, UCHIMURA T. Application of Laser Ionization Time-of-Flight Mass Spectrometry for the Direct Measurement of a Silane Coupling Agent in Slurries. ANAL SCI 2017; 33:395-397. [DOI: 10.2116/analsci.33.395] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- Takaaki FUJII
- Department of Materials Science and Engineering, Graduate School of Engineering, University of Fukui
| | - Tomohiro UCHIMURA
- Department of Materials Science and Engineering, Graduate School of Engineering, University of Fukui
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Tang S, Vinerot N, Bulatov V, Yavetz-Chen Y, Schechter I. Multiphoton electron extraction spectroscopy and its comparison with other spectroscopies for direct detection of solids under ambient conditions. Anal Bioanal Chem 2016; 408:8037-8051. [PMID: 27585917 DOI: 10.1007/s00216-016-9904-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2016] [Revised: 08/19/2016] [Accepted: 08/24/2016] [Indexed: 11/27/2022]
Abstract
Multiphoton electron extraction spectroscopy (MEES) is an analytical method for direct analysis of solids under ambient conditions in which the samples are irradiated by short UV laser pulses and the photocharges emitted are recorded as a function of the laser wavelength. The method is very sensitive, and many peaks are observed at wavelengths that are in resonance with the surface molecules. The analytical capabilities of MEES have recently been demonstrated, and here we perform a systematic comparison with some traditional spectroscopies that are commonly applied to material analysis. These include absorption, reflection, excitation and emission fluorescence, Raman, Fourier transform IR, and Fourier transform near-IR spectroscopies. The comparison is conducted for powders and for thin films of compounds that are active in all spectroscopies tested. Besides the obvious spectral parameters (signal-to-noise ratio, peak density, and resulting limits of detection), we introduce two additional variables-the spectral quality and the spectral quality density-that represent our intuitive perception of the analytical value of a spectrum. It is shown that by most parameters MEES is a superior analytical tool to the other methods tested for both sample morphologies.
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Affiliation(s)
- Shisong Tang
- Research Center for Analytical Sciences, Northeastern University, Shenyang, 110819, China
| | - Nataly Vinerot
- Schulich Faculty of Chemistry, Technion-Israel Institute of Technology, Haifa, 3200, Israel
| | - Valery Bulatov
- Research Center for Analytical Sciences, Northeastern University, Shenyang, 110819, China
| | - Yehuda Yavetz-Chen
- Research Center for Analytical Sciences, Northeastern University, Shenyang, 110819, China
| | - Israel Schechter
- Schulich Faculty of Chemistry, Technion-Israel Institute of Technology, Haifa, 3200, Israel.
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