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Countercurrent Chromatography
Countercurrent chromatography (CCC, also counter-current chromatography) is a form of liquid–liquid chromatography that uses a liquid Stationary phase (chemistry), stationary phase that is held in place by inertia of the molecules composing the stationary phase accelerating toward the center of a centrifuge due to centripetal force and is used to separate, identify, and quantify the chemical components of a mixture. In its broadest sense, countercurrent chromatography encompasses a collection of related liquid chromatography techniques that employ two Miscibility, immiscible liquid phases without a solid support. The two liquid phases come in contact with each other as at least one phase is pumped through a Chromatography column, column, a hollow tube or a series of chambers connected with channels, which contains both phases. The resulting dynamic mixing and settling action allows the components to be separated by their respective solubilities in the two phases. A wide variety of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lyman C
Lyman may refer to: Places Ukraine * Lyman, Ukraine, a city, formerly the administrative center of Lyman Raion, Donetsk Oblast * Lyman Raion, Donetsk Oblast, Ukraine, a former ''raion'' (district) * Lyman Raion, Odesa Oblast, Ukraine, a former ''raion'' United States * Lyman, Iowa, an unincorporated community * Lyman, Maine, a town * Lyman, Mississippi, a census-designated place * Lyman, Nebraska, a village * Lyman, New Hampshire, a town * Lyman, Oklahoma, a town * Lyman, South Carolina, a town * Lyman County, South Dakota ** Lyman, South Dakota, an unincorporated community in the county * Lyman, Utah, a town * Lyman, Washington, a town * Lyman, Wyoming, a town * Lyman Glacier (Mount Adams), Gifford Pinchot National Forest, Washington state * Lyman Glacier (North Cascades), Wenatchee National Forest, Washington state * Lyman Mountain, Oregon * Lyman Reservoir, Arizona Outer space * Lyman (crater), a lunar impact crater Other uses * Lyman (name), a list of people a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Distribution Constant
The distribution constant (or partition ratio) (KD) is the equilibrium constant for the distribution of an analyte in two immiscible solvents.i is the concentration of A remaining after extracting Vaq millilitre The litre ( Commonwealth spelling) or liter ( American spelling) (SI symbols L and l, other symbol used: ℓ) is a metric unit of volume. It is equal to 1 cubic decimetre (dm3), 1000 cubic centimetres (cm3) or 0.001 cubic metres (m3). A cu ...s of solution with the original concentration of sub>0 with ''i'' portions of the organic solvent, each with a volume of Vorg). References {{chromatography Chromatography ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Partition Coefficient
In the physical sciences, a partition coefficient (''P'') or distribution coefficient (''D'') is the ratio of concentrations of a chemical compound, compound in a mixture of two immiscible solvents at partition equilibrium, equilibrium. This ratio is therefore a comparison of the solubilities of the solute in these two liquids. The partition coefficient generally refers to the concentration ratio of ionization, un-ionized species of compound, whereas the distribution coefficient refers to the concentration ratio of all species of the compound (ionized plus un-ionized). In the chemistry, chemical and pharmaceutical sciences, both phases usually are solvents. Most commonly, one of the solvents is water, while the second is hydrophobic, such as 1-octanol. Hence the partition coefficient measures how hydrophilic ("water-loving") or hydrophobic ("water-fearing") a chemical substance is. Partition coefficients are useful in estimating the distribution (pharmacology), distribution of dru ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mass Transfer
Mass transfer is the net movement of mass from one location (usually meaning stream, phase, fraction, or component) to another. Mass transfer occurs in many processes, such as absorption, evaporation, drying, precipitation, membrane filtration, and distillation. Mass transfer is used by different scientific disciplines for different processes and mechanisms. The phrase is commonly used in engineering for physical processes that involve diffusive and convective transport of chemical species within physical systems. Some common examples of mass transfer processes are the evaporation of water from a pond to the atmosphere, the purification of blood in the kidneys and liver, and the distillation of alcohol. In industrial processes, mass transfer operations include separation of chemical components in distillation columns, absorbers such as scrubbers or stripping, adsorbers such as activated carbon beds, and liquid-liquid extraction. Mass transfer is often coupled to addit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Partitioning Coefficient (Kd)
Partition may refer to: Arts and entertainment Film and television * ''Partition'' (1987 film), directed by Ken McMullen * ''Partition'' (2007 film), directed by Vic Sarin * '' Partition: 1947'', or ''Viceroy's House'', a 2017 film Music * Partition (music), a segment created from a set * "Partition" (song), by Beyoncé, 2014 * ''Partition'', soundtrack to the 2007 film by Brian Tyler Law and politics * Partition (law), the division of an estate * Partition (politics), a change of political borders, including: ** Partition of India ** Partition of Ireland ** Partitions of Poland Science and technology Computing * Disk partitioning, the division of a hard disk drive * Memory partition, a memory management technique * Partition (database), the division of a logical database * Logical partition, a subset of a computer's resources, virtualized as a separate computer * Binary space partitioning, in computer science * Partition problem, in number theory and computer science Mathe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Surface-to-volume Ratio
The surface-area-to-volume ratio or surface-to-volume ratio (denoted as SA:V, SA/V, or sa/vol) is the ratio between surface area and volume of an object or collection of objects. SA:V is an important concept in science and engineering. It is used to explain the relation between structure and function in processes occurring through the surface the volume. Good examples for such processes are processes governed by the heat equation, that is, diffusion and heat transfer by thermal conduction. SA:V is used to explain the diffusion of small molecules, like oxygen and carbon dioxide between air, blood and cells, water loss by animals, bacterial morphogenesis, organism's thermoregulation, design of artificial bone tissue, artificial lungs and many more biological and biotechnological structures. For more examples see Glazier. The relation between SA:V and diffusion or heat conduction rate is explained from flux and surface perspective, focusing on the surface of a body as the place w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Immiscible
Miscibility () is the property of two chemical substance, substances to mix in all mixing ratio, proportions (that is, to fully dissolution (chemistry), dissolve in each other at any concentration), forming a homogeneity and heterogeneity, homogeneous mixture (a Solution (chemistry), solution). Such substances are said to be wikt:miscible, miscible (etymologically equivalent to the common term "wikt:mixable, mixable"). The term is most often applied to liquids but also applies to solids and gases. An example in liquids is the miscibility of water and ethanol as they mix in all proportions. By contrast, substances are said to be wikt:immiscible, immiscible if the mixture does not form a solution for certain proportions. For one example, oil is not soluble in water, so these two solvents are immiscible. As another example, butanone (methyl ethyl ketone) is immiscible in water: it is soluble in water up to about 275 grams per liter, but will separate into two Phase (matter), phases b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Normal Phase Chromatography
High-performance liquid chromatography (HPLC), formerly referred to as high-pressure liquid chromatography, is a technique in analytical chemistry used to separate, identify, and quantify specific components in mixtures. The mixtures can originate from food, chemicals, pharmaceuticals, biological, environmental and agriculture, etc., which have been dissolved into liquid solutions. It relies on high pressure pumps, which deliver mixtures of various solvents, called the mobile phase, which flows through the system, collecting the sample mixture on the way, delivering it into a cylinder, called the column, filled with solid particles, made of adsorbent material, called the stationary phase. Each component in the sample interacts differently with the adsorbent material, causing different migration rates for each component. These different rates lead to separation as the species flow out of the column into a specific detector such as UV detectors. The output of the detector is a g ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adsorption
Adsorption is the adhesion of atoms, ions or molecules from a gas, liquid or dissolved solid to a surface. This process creates a film of the ''adsorbate'' on the surface of the ''adsorbent''. This process differs from absorption, in which a fluid (the ''absorbate'') is dissolved by or permeates a liquid or solid (the ''absorbent''). While adsorption does often precede absorption, which involves the transfer of the absorbate into the volume of the absorbent material, alternatively, adsorption is distinctly a surface phenomenon, wherein the adsorbate does not penetrate through the material surface and into the bulk of the adsorbent. The term '' sorption'' encompasses both adsorption and absorption, and ''desorption'' is the reverse of sorption. Like surface tension, adsorption is a consequence of surface energy. In a bulk material, all the bonding requirements (be they ionic, covalent or metallic) of the constituent atoms of the material are fulfilled by other atoms in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Silica Gel
Silica gel is an amorphous and porosity, porous form of silicon dioxide (silica), consisting of an irregular three-dimensional framework of alternating silicon and oxygen atoms with nanometer-scale voids and pores. The voids may contain water or some other liquids, or may be filled by gas or vacuum. In the last case, the material is properly called silica Gel#Xerogels, xerogel. Silica xerogel with an average pore size of 2.4 nanometers has a strong affinity for water molecules and is widely used as a desiccant. It is hard and translucence, translucent, but considerably softer than massive silica glass or quartz, and remains hard when saturated with water. Silica xerogel is usually commercialized as coarse granules or beads, a few millimeters in diameter. Some grains may contain small amounts of indicator substance that changes color when they have absorbed some water. Small paper envelopes containing silica xerogel pellets, usually with a "do not eat" warning, are often i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microporous Material
A microporous material is a material containing pores with typical sizes less than 2 nm in diameter. Microporous materials, like mesoporous materials, are a subset of nanoporous materials. Examples of microporous materials include zeolites and metal-organic frameworks. Porous materials are classified into several kinds by their size. The recommendations of a panel convened by the International Union of Pure and Applied Chemistry The International Union of Pure and Applied Chemistry (IUPAC ) is an international federation of National Adhering Organizations working for the advancement of the chemical sciences, especially by developing nomenclature and terminology. It is ... (IUPAC) are: See page 1745. *Microporous materials have pore diameters of less than 2 nm. * Mesoporous materials have pore diameters between 2 nm and 50 nm. * Macroporous materials have pore diameters of greater than 50 nm. Micropores may be defined differently in other contexts. F ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
