One of the crucial steps in determination of sterol oxidation products (SOPs) in foods is their enrichment and purifications by various preparative methods for further analysis by GC and GC-MS. Among the preparative methods, SPE of various adsorbents and solvent systems, are being used most widely. At present, no single step SPE method is suitable to completely separate the SOPs. In this study, a SPE (1g silica) method, suitable for both transesterified and cold saponified oil samples, was developed to separate completely SOPs from other lipid components. This method resulted in high recovery from rapeseed oil of added 5beta,6beta-epoxycholestan-3beta-ol (94-96%), cholest-5-en-3beta-ol-7-one(94%), cholestane-3beta,5alpha,6beta-triol (88-91%), cholest-5-en-3beta,7alpha-diol and 5alpha,6alpha-epoxycholestan-3beta-ol (88-90%). The method has a high sample capacity of up to 1g transesterified or cold-saponified oil sample. The method was tested and applied to different vegetable oils and to monitor the effects of refining processes on POPs in hazelnut oil.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1016/j.chroma.2008.11.041 | DOI Listing |
Polymers (Basel)
December 2024
Institute of Chemistry, Federal University of Rio Grande do Sul (UFRGS), Bento Gonçalves 9500, Porto Alegre 90010-150, RS, Brazil.
This study reported a one-spot preparation of magnetic composite carbon (MCC@Fe) from microcrystalline cellulose (MC). The pure cellulose was impregnated in iron (III) chloride solution and carbonized at 650 °C. The MCC@Fe composite adsorbent underwent various characterization techniques.
View Article and Find Full Text PDFPolymers (Basel)
December 2024
Center for Chemical Engineering, ITMO University, Kronverkskiy Prospekt, 49, 197101 Saint-Petersburg, Russia.
In this work, three carboxymethyl starches (CMS) were obtained by the two-step reaction process of carboxymethylation with different degrees of substitution (0.16, 0.33, and 0.
View Article and Find Full Text PDFPharmaceuticals (Basel)
December 2024
N. P. Bechtereva Institute of the Human Brain, Russian Academy of Sciences, 197022 St. Petersburg, Russia.
-succinimidyl-[F]fluorobenzoate ([F]SFB) is commonly prepared through a three-step procedure starting from [F]fluoride ion. A number of methods for the single-step radiosynthesis of [F]SFB have been introduced recently, including the radiofluorination of diaryliodonium salts and the Cu-mediated F-fluorination of pinacol aryl boronates and aryl tributyl stannanes, but they still have the drawbacks of lengthy product purification procedures. In the present work, two approaches for the direct labeling of [F]SFB from diaryliodonium (DAI) salt () and pinacol aryl boronate () are evaluated, with a major focus on developing a fast and simple SPE-based purification procedure.
View Article and Find Full Text PDFMicromachines (Basel)
November 2024
Department of Mechanical Engineering, National Yang Ming Chiao Tung University, Hsinchu 30010, Taiwan.
This study introduces a novel deposition technique capable of depositing thin films with any arbitrary thickness profile. The apparatus consists of a fixed shadow mask and a rotating sample carrier plate. The shadow mask features a specifically designed opening curve that corresponds to the particular thickness profile of the deposited film.
View Article and Find Full Text PDFMolecules
December 2024
Laboratory of Chemistry and Technology of Polymers and Colors, Department of Chemistry, Aristotle University of Thessaloniki, GR-54124 Thessaloniki, Greece.
This study presents the synthesis and characterization of a series of multiblock copolymers, poly(ethylene 2,5-furandicarboxylate)-poly(ε-caprolactone) (PEF-PCL), created through a combination of the two-step melt polycondensation method and ring opening polymerization, as sustainable alternatives to fossil-based plastics. The structural confirmation of these block copolymers was achieved through Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy (ATR-FTIR), ensuring the successful integration of PEF and PCL segments. X-ray Photoelectron Spectroscopy (XPS) was employed for chemical bonding and quantitative analysis, providing insights into the distribution and compatibility of the copolymer components.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!