Resonance-enhanced multiphoton ionization time-of-flight mass spectrometry for direct analysis of liposome-encapsulated compounds.

The direct measurement of compounds encapsulated into liposomes without pretreatment allows verification of both the encapsulation efficiency and the release rate of liposomes in their original state. In the present study, the direct analysis of liposomes was conducted via resonance-enhanced multiphoton ionization time-of-flight mass spectrometry (REMPI-TOFMS). When analyte species (2-phenoxyethanol) encapsulated in liposomes were measured online, spike signals appeared in a time profile of the peak area for 2-phenoxyethanol, which suggested a dispersion of the compound in this sample.

Sample preparation conditions for the real-time measurement of W/O emulsions by resonance-enhanced multiphoton ionization time-of-flight mass spectrometry.

Analysis of an emulsion in its original dispersed condition is quite important for quality assessment and quality control. In the present study, the practical experimental conditions of the real-time measurement of a water-in-oil (W/O) emulsion were examined via resonance-enhanced multiphoton ionization time-of-flight mass spectrometry (REMPI-TOFMS). A W/O emulsion was prepared using cyclohexane as the oil phase with toluene as an analyte species.

Optimization of Sulfide Annealing Conditions for AgSnS Thin Films.

AgSnS (ATS) has been reported to have a band gap of 1.33 eV and is expected to be a suitable material for the light-absorbing layers of compound thin-film solar cells. However, studies on solar cells that use ATS are currently lacking.

Handedness anomaly in a non-collinear antiferromagnet under spin-orbit torque.

Non-collinear antiferromagnets are an emerging family of spintronic materials because they not only possess the general advantages of antiferromagnets but also enable more advanced functionalities. Recently, in an intriguing non-collinear antiferromagnet MnSn, where the octupole moment is defined as the collective magnetic order parameter, spin-orbit torque (SOT) switching has been achieved in seemingly the same protocol as in ferromagnets. Nevertheless, it is fundamentally important to explore the unknown octupole moment dynamics and contrast it with the magnetization vector of ferromagnets.

Characterization of Cooked Nonglutinous Rice Cultivars Based on Flavor Volatiles and Their Change during Storage.

Characterizing fleshly cooked rice cultivars according to the volatile aroma compounds helps consumers select a favorite and is useful for the development of new cultivars that will have a pleasant aroma. In the present study, six Japanese nonglutinous cultivars, which were freshly harvested in 2021, were characterized based on their flavor volatiles after being freshly cooked. In order to extract the volatile compounds just after cooking, the vaporized compounds were extracted for 5 min using a solid-phase microextraction (SPME) fiber and were measured via gas chromatography/mass spectrometry (GC/MS).

Using Resonance-Enhanced Multiphoton Ionization Time-of-Flight Mass Spectrometry to Evaluate the Movement of a Constituent in a Multiple Emulsion.

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 (O/W/O) emulsion was prepared using a two-step emulsification method with styrene as an analyte species in the inner phase (O). The emulsion was measured using resonance-enhanced multiphoton ionization time-of-flight mass spectrometry without pretreatment such as centrifugation.

Quantitative Evaluation of the Creaming of Emulsions via Resonance-Enhanced Multiphoton Ionization Time-of-Flight Mass Spectrometry.

The creaming behavior of an oil-in-water (O/W) emulsion was quantitatively evaluated via resonance-enhanced multiphoton ionization time-of-flight mass spectrometry. Styrene O/W emulsions were prepared with initial styrene concentrations of 1 and 4 g/L, and the height at the center of the sample was monitored. A peak area of the molecular ion of styrene was set as the signal intensity, for which a time profile was constructed from a series of mass spectra.

Correction to "Using Resonance-Enhanced Multiphoton Ionization Time-of-Flight Mass Spectrometry to Quantitatively Analyze the Creaming of an Emulsion".

[This corrects the article DOI: 10.1021/acsomega.9b02930.

Characteristic Signal Behaviors for Water-in-Oil and Oil-in-Water Emulsions Measured by Resonance-Enhanced Multiphoton Ionization Time-of-Flight Mass Spectrometry.

Resonance-enhanced multiphoton ionization time-of-flight mass spectrometry (REMPI-TOFMS) was used to study the characteristic signal behaviors obtained from two types of emulsions: water-in-oil (W/O) and oil-in-water (O/W). All emulsions were prepared using phase inversion emulsification, i.e.

Using SPME-GC/REMPI-TOFMS to Measure the Volatile Odor-Active Compounds in Freshly Cooked Rice.

The volatile odor-active compounds of cooked rice were evaluated using a method that combined solid-phase microextraction (SPME) with gas chromatography-resonance-enhanced multiphoton ionization time-of-flight mass spectrometry (GC/REMPI-TOFMS). An SPME fiber was held at the upper levels of the cooked rice and given an extraction time of 5 min. By using a nanosecond ultraviolet (266 nm) pulsed laser for ionization, two compounds, 4-vinylphenol and indole, which are considered to be important for the characteristic flavor of cooked rice, could be detected from all types of cultivars measured in the present study-nonglutinous rice, glutinous rice, and aromatic rice.

Using Resonance-Enhanced Multiphoton Ionization Time-of-Flight Mass Spectrometry to Quantitatively Analyze the Creaming of an Emulsion.

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.

Evaluating the Creaming of an Emulsion via Mass Spectrometry and UV-Vis Spectrophotometry.

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.

Resonance-enhanced Multiphoton Ionization Time-of-Flight Mass Spectrometry for Evaluating Emulsion Inversion via Temperature Change.

This study used resonance-enhanced multiphoton ionization time-of-flight mass spectrometry (REMPI-TOFMS) to evaluate the phase inversion that is driven via temperature change. A change in temperature prompts phase inversion in an oil-in-water (O/W) emulsion that uses a nonionic surfactant as an emulsifier. In this study, an O/W emulsion was prepared containing Triton X-100 as an emulsifier.

A Quantitative Analysis of an Oil Component in an Emulsion by Multiphoton Ionization Mass Spectrometry.

The first quantitative analysis of an oil component in an emulsion was achieved by multiphoton ionization time-of-flight mass spectrometry (MPI-TOFMS). An oil-in-water (O/W) emulsion was prepared. Styrene (0 - 5000 ng μL) and Triton X-100 were used as the oil phase and the disperser, respectively.

Online Monitoring of a Styrene Monomer and a Dimer in an Emulsion via Laser Ionization Time-of-Flight Mass Spectrometry.

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.

Application of Laser Ionization Time-of-Flight Mass Spectrometry for the Direct Measurement of a Silane Coupling Agent in Slurries.

Laser ionization time-of-flight mass spectrometry (LI-TOFMS) was applied to the direct measurement of a silane coupling agent in slurries. In the present study, a slurry with dispersed TiO nanoparticles treated with phenyltriethoxysilane (PTES) was prepared. As a result, the peaks for PTES could be observed from the slurry sample containing unreacted PTES, and no peaks were observed from the slurry sample where unreacted PTES was removed by washing.

Time-Profile Measurement of an Emulsion Using Multiphoton Ionization Time-of-Flight Mass Spectrometry in Combination with a Microscope.

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.

Evaluating the Translational Temperature of Molecules Laser-desorbed after Online Concentration Using Multiphoton Ionization Time-of-Flight Mass Spectrometry.

We describe a new technique for evaluating the translational temperature of molecules by applying online concentration via analyte adsorption/laser desorption, which is a sample-introduction technique for resonance-enhanced multiphoton ionization time-of-flight mass spectrometry (REMPI-TOFMS). In the present study, analyte molecules were adsorbed via a narrowed capillary tip once, and then the flow of the carrier gas containing the analyte was stopped. After laser desorption, the ion signals induced by REMPI were monitored.

Evaluating the Aging of Multiple Emulsions Using Resonance-Enhanced Multiphoton Ionization Time-of-Flight Mass Spectrometry.

Resonance-enhanced multiphoton ionization time-of-flight mass spectrometry was applied to measurements of multiple emulsions with no pretreatment; a method for the quantitative evaluation of aging was proposed. We prepared water-in-oil-in-water (W/O/W) multiple emulsions containing toluene and m-phenylenediamine. The samples were measured immediately following both preparation and after having been stirred for 24 h.

Multiphoton Ionization Time-of-Flight Mass Spectrometry for the Detection of Bioactive Lignan.

Multiphoton ionization time-of-flight mass spectrometry (MPI-TOFMS) combined with a pulsed laser for sample vaporization was developed for the detection of a low-volatile compound in a solution. A solution containing Taiwanin A ((3E,4E)-3,4-bis(1,3-benzodioxol-5-ylmethylene)dihydro-2(3H)-furanone), which is a lignan that has an anticancer effect, was employed in the present study. Consequently, Taiwanin A could be detected by irradiating a laser pulse for vaporization to an inlet nozzle, rather than by heating.

Applying fluorescence lifetime imaging microscopy to evaluate the efficacy of anticancer drugs.

Fluorescence lifetime imaging microscopy was applied to evaluate the efficacy of anticancer drugs. A decrease in the fluorescence lifetime of the nucleus in apoptotic cancer cells stained by SYTO 13 dye was detected after treatment with antitumor antibiotics such as doxorubicin or epirubicin. It was confirmed that the change in fluorescence lifetime occurred earlier than morphological changes in the cells.

Pyrolysis-gas chromatography/multiphoton ionization/time-of-flight mass spectrometry for the rapid and selective analysis of polycyclic aromatic hydrocarbons in aerosol particulate matter.

Gas chromatography/multiphoton ionization/time-of-flight mass spectrometry (GC/MPI/TOFMS) coupled with a Curie-point pyrolyzer as a sample introduction technique was applied for the rapid and selective analysis of the polycyclic aromatic hydrocarbons (PAHs) that are a part of aerosol particulate matter. Increasing the operating temperature of the pyrolyzer also increased the number of observed peaks, but the peak areas of a few PAHs decreased due to thermal decomposition. In the present study, more than 100 peaks were confirmed using 0.

Resonance-enhanced multiphoton ionization/time-of-flight mass spectrometry for sensitive analysis of product ions formed by online concentration from analyte adsorption/laser desorption.

Resonance-enhanced multiphoton ionization/time-of-flight mass spectrometry (REMPI/TOFMS) was developed for the analysis of product ions formed by online concentration/laser desorption (Online COLD). In the online COLD system, which is one of the sample introduction techniques for REMPI/TOFMS, the analyte molecules are adsorbed at the tip of the capillary column and then are heated and vaporized by introducing a desorption laser. In the present study, the molecules concentrated at the tip reacted to the application of an intense desorption laser.