A novel sample-pretreatment method for time-of-flight secondary ion mass spectrometry (TOF-SIMS) was developed using supercritical fluid extraction (SFE). In SFE, the extraction efficiency of a certain organic matter is controlled by the pressure and temperature of supercritical CO2. Two-step SFE (1st step at 10 Mpa, 40 degrees C; 2nd step at 30 MPa, 120 degrees C) was applied to diesel exhaust particles containing many kinds of n-alkanes and aromatic species. n-Alkanes and polycyclic aromatic hydrocarbons (PAHs) were extracted in the 1st and 2nd steps, respectively. This selectivity was utilized for the sample preparation of TOF-SIMS analysis. Diesel exhaust particles after the 1st step of extraction were analyzed with TOF-SIMS, aiming at PAHs as analytical targets. The obtained spectrum was simplified, and mass peaks of individual PAHs were easily assigned, because unwanted compounds, like n-alkanes, were selectively removed by SFE. Furthermore, a simple calculation elucidated the outline of the spectrum.
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http://dx.doi.org/10.2116/analsci.20.1379 | DOI Listing |
Heliyon
January 2025
Department of Food Science and Engineering, Hamedan Branch, Islamic Azad University, Hamedan, Iran.
Supercritical CO modified by polar solvents can extract a wide variety of polar and non-polar chemical components compared to conventional methods. The current study aims to extract Rivas (Rheum ribes) flower using the ethanol modified supercritical CO (SCO-EOH) method; analyze its chemical compounds and bioactivity, encapsulate the extract in maltodextrin, gum-Arabic (GA), and their combination (GA + MD) using the spray drying method and investigate the differences among microparticles using Principal Component Analysis (PCA). The Rivas extract obtained by the SCO-EOH method was a rich source of unsaturated fatty acids (mainly linoleic acid: 57.
View Article and Find Full Text PDFCurr Med Chem
January 2025
School of Pharmacy, Changzhou University, Changzhou, 213164, China.
Curcumin is a natural plant pigment that has been widely used in food production, drug development, and textile engineering. Gaining a deep understanding of the biological activities of curcumin and obtaining high-purity curcumin are of vital importance for basic research and applications of curcumin. In this review, we summarize recent advances in curcumin, mainly focusing on the methods of extracting and purifying curcumin from turmeric as well as applications based on biological activity.
View Article and Find Full Text PDFJ Colloid Interface Sci
January 2025
International Research Center for Renewable Energy (IRCRE), State Key Laboratory of Multiphase Flow in Power Engineering (MFPE), Xi'an Jiaotong University (XJTU), Xi'an 710049 PR China.
Graphitic carbon nitride (g-CN) has been regarded as highly potential photocatalyst for solar energy utilization. However, the restricted absorption of visible light for pristine g-CN significantly limits the solar-light-driven chemical reaction efficiency. Herein, structurally distorted g-CN nanosheets with awakened n-π* electron transition were successfully synthesized through hexamethylenetetramine (HMTA)-involved supercritical CO (scCO) treatment and following pyrolysis of melamine precursor.
View Article and Find Full Text PDFEnviron Sci Pollut Res Int
January 2025
Council for Geoscience, Private Bag X112, Pretoria, 0001, South Africa.
One-step high-pressure and high-temperature direct aqueous mineral carbonation of tailings derived from mining of Platinum Group Metals in South Africa requires a fundamental understanding of the reactivity of the most dominant mineral phases, i.e. pyroxene and plagioclase (66 wt.
View Article and Find Full Text PDFMolecules
January 2025
Hainan Key Laboratory of Storage and Processing of Fruits and Vegetables, Agricultural Products Processing Research Institute, Chinese Academy of Tropical Agricultural Sciences, Zhanjiang 524001, China.
This study aimed to determine the chemical composition of five essential oils (LEOs) using the gas chromatography-mass spectroscopy technique and to assess their antibacterial activity against four marine species, including , , , and . Sensitivity tests were performed using the disk diffusion and serial dilution methods. The results showed that all five LEOs exhibited antibacterial activity against the four tested marine species.
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