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Showing 1 to 20 of 46 for “"Polar compounds"”.
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Analysis of polar compounds by supercritical fluid chromatography
The analysis of polar compounds has been studied by SFC using 100% CO₂ or methanol modified CO₂ as the mobile phase. Both microbore packed and capillary columns are employed to separate the mixtures of steroids and agricultural compounds of various chemical classes such as amides, sulfonamides and …
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Feasibility of analysis of polar compounds by high performance liquid chromatography with Fourier transform infrared spectroscopic detection
… spectroscopic detection were developed for polar compounds including phenols, alcohols, amines and azaarenes. Detection by FTIR gave information concerning hydrogen bonding and solvent effects occurring during the separations in addition to giving structural information about eluted species …
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Metabolism of testosterone by tissue enzymes
… to [triangle]^4-androstene-3, 17-dione and "polar compounds" has been established. Several enzyme systems are felt to be active in testosterone breakdown by human skin; some of these from "polar compounds", one of them forms [triangle]^4-androstene-3,17-dione, while others form additional …
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The effects of thermally abused frying oil polar fraction on breast cancer motility and proliferation in vitro
… abused frying oil (TAFO), separate the TAFO polar fraction (TAFO-PF), and investigate the impact of the TAFO-PF on mammary carcinoma cells in vitro. The typical American consumes approximately 2,000 kilocalories per day, with approximately 33% of calories derived from fat. It is estimated …
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Effects of oil types and beta-carotene in repeated deep-fat frying of French fries
… 100 cycles. With respect to the content of total polar compounds, the stability of the oils decreased in the order of palm stearin > soybean oil = palm olein at 100 cycles. Heated control oils showed much lower content of free fatty acids than fried oils with French fries. Palm stearin showed …
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The Analysis of Flavor Compounds in Green Tea Using Ice Concentration Linked with Extractive Stirrer (Icecles)
… especially for the extraction of relatively polar compounds, which may prove to have widespread applicability for analytical sample preparation. ICECLES was used to prepare green tea for flavor analysis by gas chromatography-mass spectrometry (GC-MS). ICECLES produce 301 constituents, the …
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Chemically modified polymeric resins for high performance liquid chromatography, solid-phase extraction and organic separation by LC and GC
… the chromatographic behavior of various test compounds on PS/DVB resin. On the hydrophilically modified resins, the capacity factors (k[superscript]') of polar compounds (such as phenol, p-cresol) are increased, while the k[superscript]' of non-polar compounds (such as toluene, cumene) are …
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Formation and transport of undesirable compounds during repeated deep frying
… it also results in development of undesirable compounds especially when oil is repeatedly reutilized. Once these reutilized oils reach a stage where they show visible signs of deterioration due to repeat frying cycles, they can be considered as thermally abused Frying oil (TAFO). Consumption of …
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Supercritical fluid extraction as a sample preparation technique for the isolation of polar pharmaceutical compounds
The low polarity of the supercritical fluid extraction (SFE) solvent, CO₂, causes problems when applying this technique to polar compounds. The objective of this research was to expand the applicability of SFE to include polar compounds. The first phase of this research investigated "inverse SFE", …
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The Fractionation of Crude Petroleum using Chromatography, Extrography and Supercritical Fluid Extraction
… GC-MS. The recoveries of saturated, aromatic and polar compounds from crude oil are in the range of 60.6-70.3 %, 12.9-19.8 % and 7.1-9.4 % respectively, with relative standard deviations under 6 %.<br/> <br/>The potential of extrography on silica gel as a fractionation technique of crude oil has …
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Invention and implementation of technologies for continuous flow synthesis
… to produce the salt of nicardipine and wash away polar compounds. Then, the product is extracted into the aqueous layer by using a 1:1 water DMSO mixture.
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Isolation and characterisation of antibiotic-producing marine actinomycetes
… Partial purification of the active compounds was carried out on the three strains exhibiting strong antibacterial activity. All were shown to produce moderately to highly polar compounds.
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Supercritical Fluid Extraction Directly Coupled with Reversed Phase Liquid Chromatography for Quantitative Analysis of Analytes in Complex Matrices
… confirmed the presence of the major degradation compounds of hyperforin (i.e. furohyperforin and two of its analogues). Thus, the degradation process must have occurred during plant drying or storage. The feasibility of quantitative extraction and analysis of hyperforin by on-line SFE-LC was made …
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The development of deoxynybomycins as potent and selective antibiotics against fluoroquinolone resistant bacteria
… 2 is the synthesis of several new DNM based compounds containing either previously unexplored polar functionality or new modifications to the five-membered ring. These compounds were tested against fluoroquinolone resistant and wild-type S. aureus, and the derivatives based on modifying the …
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Characterisation and Screening of secondary metabolites from Commiphora viminea (Burtt Davy, Burseraceae) Engl. for antifungal properties against Candida auris
… as a result of their abundance of bioactive compounds with antioxidant, antimicrobial, and anticancer properties. Commiphora viminea, belonging to the Burseraceae family, has been traditionally utilised for its medicinal and aromatic qualities; however, its phytochemical profile and …
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Conformational and Structural Determinations of Substituted Four and Five Membered Rings by Infrared, Raman, and Microwave Spectral Studies
… solutions to improve conformational stuies of polar compounds or compounds with four or more conformers. Additionally chirped-pulse FT microwave spectroscopy has been applied to structural problems to greatly improve the structural parameters.
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Structure, distribution and innervation of sensilla on the ovipositor of the spruce budworm Choristoneura fumiferana, and electrophysiological reponses from type II sensilla
… sensilla responded differently to common polar nutrients. Results from this study suggest that mated females may be using polar compounds rather than the surface waxes to locate potential hosts.
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Analysis of polymeric extractives of Western Juniper (Juniperus occidentalis) heartwood
… by the brine shrimp lethal bioassay. Less polar compounds with a low molecular weight average possess a high toxicity therefore contribute to the overall durability of this species. More polar fractions with higher molecular weight averages are non-toxic. The polymeric material with …
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Investigation of Binding of Volatile Flavor Compounds by Soy Proteins in Low -Moisture Food Systems by Inverse Gas Chromatography (Igc)
… while stronger binding exhibited on those more polar compounds (ester, ketone, aldehyde, alcohol) might be ascribed to both specific and non-specific interactions (hydrogen bonding, dipole and van der Walls dispersion forces). Interaction potential of polar flavor compounds with SPI was greatly …
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Development of chemosensors for endocrine disrupting chemicals (EDCs): synthesis and evaluation of solid-phase bound receptors
… efficiency of the pollutants depends on their polarity. Thus polar compounds stay in the water sample while apolar compounds are retained on the solid phase. As a consequence the selectivity of the SPE is poor. A solid-phase material which could selectively bind the different EDCs would thus …
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