Chromatography, Supercritical Fluid
A CHROMATOGRAPHY method using supercritical fluid, usually carbon dioxide under very high pressure (around 73 atmospheres or 1070 psi at room temperature) as the mobile phase. Other solvents are sometimes added as modifiers. This is used both for analytical (SFC) and extraction (SFE) purposes.
Chromatography, High Pressure Liquid
Carbon Dioxide
Chromatography, Affinity
Chromatography
Techniques used to separate mixtures of substances based on differences in the relative affinities of the substances for mobile and stationary phases. A mobile phase (fluid or gas) passes through a column containing a stationary phase of porous solid or liquid coated on a solid support. Usage is both analytical for small amounts and preparative for bulk amounts.
Chromatography, Gas
Fractionation of a vaporized sample as a consequence of partition between a mobile gaseous phase and a stationary phase held in a column. Two types are gas-solid chromatography, where the fixed phase is a solid, and gas-liquid, in which the stationary phase is a nonvolatile liquid supported on an inert solid matrix.
Solvents
Liquids that dissolve other substances (solutes), generally solids, without any change in chemical composition, as, water containing sugar. (Grant & Hackh's Chemical Dictionary, 5th ed)
Chromatography, Gel
Hedeoma
Chromatography, Ion Exchange
Separation technique in which the stationary phase consists of ion exchange resins. The resins contain loosely held small ions that easily exchange places with other small ions of like charge present in solutions washed over the resins.
Calophyllum
Pressure
Hexanes
Chromatography, Thin Layer
Chromatography on thin layers of adsorbents rather than in columns. The adsorbent can be alumina, silica gel, silicates, charcoals, or cellulose. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
Drug Residues
Powders
Gas Chromatography-Mass Spectrometry
A microanalytical technique combining mass spectrometry and gas chromatography for the qualitative as well as quantitative determinations of compounds.
Methanol
A colorless, flammable liquid used in the manufacture of FORMALDEHYDE and ACETIC ACID, in chemical synthesis, antifreeze, and as a solvent. Ingestion of methanol is toxic and may cause blindness.
Thermogravimetry
Technique whereby the weight of a sample can be followed over a period of time while its temperature is being changed (usually increased at a constant rate).
Ionic Liquids
Salts that melt below 100 C. Their low VOLATILIZATION can be an advantage over volatile organic solvents.
Solubility
Technology, Pharmaceutical
The application of scientific knowledge or technology to pharmacy and the pharmaceutical industry. It includes methods, techniques, and instrumentation in the manufacture, preparation, compounding, dispensing, packaging, and storing of drugs and other preparations used in diagnostic and determinative procedures, and in the treatment of patients.
Coriandrum
Industrial Waste
Plant Extracts
Epitestosterone
The 17-alpha isomer of TESTOSTERONE, derived from PREGNENOLONE via the delta5-steroid pathway, and via 5-androstene-3-beta,17-alpha-diol. Epitestosterone acts as an antiandrogen in various target tissues. The ratio between testosterone/epitestosterone is used to monitor anabolic drug abuse.
Pesticide Residues
Chemical Fractionation
Separation of a mixture in successive stages, each stage removing from the mixture some proportion of one of the substances, for example by differential solubility in water-solvent mixtures. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
Silica Gel
A non-crystalline form of silicon oxide that has absorptive properties. It is commonly used as a desiccating agent and as a stationary phase for CHROMATOGRAPHY. The fully hydrated form of silica gel has distinct properties and is referred to as SILICIC ACID.
Etiocholanolone
The 5-beta-reduced isomer of ANDROSTERONE. Etiocholanolone is a major metabolite of TESTOSTERONE and ANDROSTENEDIONE in many mammalian species including humans. It is excreted in the URINE.
Drug Compounding
Temperature
The property of objects that determines the direction of heat flow when they are placed in direct thermal contact. The temperature is the energy of microscopic motions (vibrational and translational) of the particles of atoms.
Chemistry, Pharmaceutical
Rosa
Liquid-Liquid Extraction
Nanocapsules
Polygala
Oils, Volatile
Oils which evaporate readily. The volatile oils occur in aromatic plants, to which they give odor and other characteristics. Most volatile oils consist of a mixture of two or more TERPENES or of a mixture of an eleoptene (the more volatile constituent of a volatile oil) with a stearopten (the more solid constituent). The synonym essential oils refers to the essence of a plant, as its perfume or scent, and not to its indispensability.
Chemistry Techniques, Analytical
Mass Spectrometry
Sideritis
Acorus
A plant genus of the family ACORACEAE, order Arales, subclass Arecidae most notable for Acorus calamus L. root which contains asarone and has been used in TRADITIONAL MEDICINE.
Catharanthus
Sterilization
Volatilization
A phase transition from liquid state to gas state, which is affected by Raoult's law. It can be accomplished by fractional distillation.
Laurus
A plant genus in the LAURACEAE family. Laurus nobilis L. leaves are known for use in SPICES, having a similar flavor as UMBELLULARIA.
Sulfamethazine
Chromatography, DEAE-Cellulose
A type of ion exchange chromatography using diethylaminoethyl cellulose (DEAE-CELLULOSE) as a positively charged resin. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
Food Contamination
Water
Cardenolides
C(23)-steroids with methyl groups at C-10 and C-13 and a five-membered lactone at C-17. They are aglycone constituents of CARDIAC GLYCOSIDES and must have at least one double bond in the molecule. The class includes cardadienolides and cardatrienolides. Members include DIGITOXIN and DIGOXIN and their derivatives and the STROPHANTHINS.
Distillation
Porosity
Polymers
Calorimetry, Differential Scanning
Silicon Dioxide
Transparent, tasteless crystals found in nature as agate, amethyst, chalcedony, cristobalite, flint, sand, QUARTZ, and tridymite. The compound is insoluble in water or acids except hydrofluoric acid.
Electrophoresis, Polyacrylamide Gel
Microscopy, Electron, Scanning
Microscopy in which the object is examined directly by an electron beam scanning the specimen point-by-point. The image is constructed by detecting the products of specimen interactions that are projected above the plane of the sample, such as backscattered electrons. Although SCANNING TRANSMISSION ELECTRON MICROSCOPY also scans the specimen point by point with the electron beam, the image is constructed by detecting the electrons, or their interaction products that are transmitted through the sample plane, so that is a form of TRANSMISSION ELECTRON MICROSCOPY.
Flurbiprofen
Chemical Precipitation
Chromatography, Agarose
A method of gel filtration chromatography using agarose, the non-ionic component of agar, for the separation of compounds with molecular weights up to several million.
Lignans
A class of dibenzylbutane derivatives which occurs in higher plants and in fluids (bile, serum, urine, etc.) in man and other animals. These compounds, which have a potential anti-cancer role, can be synthesized in vitro by human fecal flora. (From Singleton & Sainsbury, Dictionary of Microbiology and Molecular Biology, 2d ed)
Stearic Acids
Indicators and Reagents
Substances used for the detection, identification, analysis, etc. of chemical, biological, or pathologic processes or conditions. Indicators are substances that change in physical appearance, e.g., color, at or approaching the endpoint of a chemical titration, e.g., on the passage between acidity and alkalinity. Reagents are substances used for the detection or determination of another substance by chemical or microscopical means, especially analysis. Types of reagents are precipitants, solvents, oxidizers, reducers, fluxes, and colorimetric reagents. (From Grant & Hackh's Chemical Dictionary, 5th ed, p301, p499)
Stereoisomerism
Solutions
Microwaves
X-Ray Diffraction
The scattering of x-rays by matter, especially crystals, with accompanying variation in intensity due to interference effects. Analysis of the crystal structure of materials is performed by passing x-rays through them and registering the diffraction image of the rays (CRYSTALLOGRAPHY, X-RAY). (From McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
Carotenoids
Chromatography, Reverse-Phase
A chromatography technique in which the stationary phase is composed of a non-polar substance with a polar mobile phase, in contrast to normal-phase chromatography in which the stationary phase is a polar substance with a non-polar mobile phase.