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Solid Phase Extraction
Solid-phase extraction (SPE) is an extractive technique by which compounds that are dissolved or suspended in a liquid mixture are separated from other compounds in the mixture according to their physical and chemical properties. Analytical laboratories use solid phase extraction to concentrate and purify samples for analysis. Solid phase extraction can be used to isolate analytes of interest from a wide variety of matrices, including urine, blood, water, beverages, soil, and animal tissue. SPE uses the affinity of solutes dissolved or suspended in a liquid (known as the mobile phase) for a solid through which the sample is passed (known as the stationary phase) to separate a mixture into desired and undesired components. The result is that either the desired analytes of interest or undesired impurities in the sample are retained on the stationary phase. The portion that passes through the stationary phase is collected or discarded, depending on whether it contains the desired ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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SPE Manifold
SPE may refer to: Science and technology * Spe (planet), 14 Andromedae b * Serum protein electrophoresis * Solar particle event,generating very high energy protons * Solid phase extraction, from a mixture * Solid-phase epitaxy, from amorphous to crystalline * ''The Sound Pattern of English'', a 1968 book by Noam Chomsky and Morris Halle * Stanford prison experiment, in psychology * Synchronous payload envelope, in synchronous optical networking * SpE, abbreviation for Sporadic E propagation Computer science * Synergistic Processing Element in the Cell microprocessor * Signal-Processing Engine, for example in the PowerPC e500 * Single-Pair Ethernet Organizations * Sauber Petronas Engineering, car engine manufacturer * Societas Privata Europaea, a Europe-wide type of limited company * Sony Pictures Entertainment, a US company * SPE, later Luminus (company) * Special Police Establishment, later Central Bureau of Investigation, India * Special purpose entity, for a specific pur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Solid-phase Microextraction
Solid phase microextraction, or SPME, is a solid phase extraction sampling technique that involves the use of a fiber coated with an extracting phase, that can be a liquid (polymer) or a solid (sorbent), which extracts different kinds of analytes (including both volatile and non-volatile) from different kinds of media, that can be in liquid or gas phase. The quantity of analyte extracted by the fibre is proportional to its concentration in the sample as long as equilibrium is reached or, in case of short time pre-equilibrium, with help of convection or agitation. Analysis After extraction, the SPME fiber is transferred to the injection port of separating instruments, such as a gas chromatography and mass spectrometry, where desorption of the analyte takes place and analysis is carried out. Advantages The attraction of SPME is that the extraction is fast, simple, can be done usually without solvents, and detection limits can reach parts per trillion (ppt) levels for certain comp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Convection
Convection is single or multiphase fluid flow that occurs spontaneously due to the combined effects of material property heterogeneity and body forces on a fluid, most commonly density and gravity (see buoyancy). When the cause of the convection is unspecified, convection due to the effects of thermal expansion and buoyancy can be assumed. Convection may also take place in soft solids or mixtures where particles can flow. Convective flow may be transient (such as when a multiphase mixture of oil and water separates) or steady state (see Convection cell). The convection may be due to gravitational, electromagnetic or fictitious body forces. Heat transfer by natural convection plays a role in the structure of Earth's atmosphere, its oceans, and its mantle. Discrete convective cells in the atmosphere can be identified by clouds, with stronger convection resulting in thunderstorms. Natural convection also plays a role in stellar physics. Convection is often cate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Chemical Equilibrium
In a chemical reaction, chemical equilibrium is the state in which both the reactants and products are present in concentrations which have no further tendency to change with time, so that there is no observable change in the properties of the system. This state results when the forward reaction proceeds at the same rate as the reverse reaction. The reaction rates of the forward and backward reactions are generally not zero, but they are equal. Thus, there are no net changes in the concentrations of the reactants and products. Such a state is known as dynamic equilibrium. Historical introduction The concept of chemical equilibrium was developed in 1803, after Berthollet found that some chemical reactions are reversible. For any reaction mixture to exist at equilibrium, the rates of the forward and backward (reverse) reactions must be equal. In the following chemical equation, arrows point both ways to indicate equilibrium. A and B are reactant chemical species, S and T a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Volatility (chemistry)
In chemistry, volatility is a material quality which describes how readily a substance vaporizes. At a given temperature and pressure, a substance with high volatility is more likely to exist as a vapour, while a substance with low volatility is more likely to be a liquid or solid. Volatility can also describe the tendency of a vapor to condense into a liquid or solid; less volatile substances will more readily condense from a vapor than highly volatile ones. Differences in volatility can be observed by comparing how fast substances within a group evaporate (or sublimate in the case of solids) when exposed to the atmosphere. A highly volatile substance such as rubbing alcohol (isopropyl alcohol) will quickly evaporate, while a substance with low volatility such as vegetable oil will remain condensed. In general, solids are much less volatile than liquids, but there are some exceptions. Solids that sublimate (change directly from solid to vapor) such as dry ice (solid carbon dio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Analyte
An analyte, component (in clinical chemistry), or chemical species is a substance or chemical constituent that is of interest in an analytical procedure. The purest substances are referred to as analytes, such as 24 karat gold, NaCl, water, etc. In reality, no substance has been found to be 100% pure in its quality, so a substance that is found to be most pure (for some metals, 99% after electrolysis) is called an analyte. See also *Analytical chemistry * Immunoassay *Magnetic immunoassay Magnetic immunoassay (MIA) is a type of diagnostic immunoassay using magnetic beads as labels in lieu of conventional enzymes (ELISA), radioisotopes ( RIA) or fluorescent moieties ( fluorescent immunoassays) to detect a specified analyte. MIA invo ... References Analytical chemistry {{Analytical-chemistry-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Sorbent
A sorbent is a material used to absorb or adsorb liquids or gases. Examples include: *A material similar to molecular sieve material, which acts by adsorption (attracting molecules to its surface). It has a large internal surface area and good thermal conductivity. It is typically supplied in pellets of 1 mm to 2 mm diameter and roughly 5 mm length or as grains of the order 1 mm. Occasionally as beads up to 5 mm diameter. They are typically made from aluminium oxide with a porous structure. *Materials used to absorb other materials due to their high affinity for doing so. Examples include: **In composting, dry (brown, high-carbon) materials absorb many odoriferous chemicals, and these chemicals help to decompose these sorbents. **A sponge absorbs many times its own weight in water. **A polypropylene fiber mat may be used to absorb oil. **A cellulose fiber product may be used to absorb oil. **The granular gel material in a baby diaper will absorb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Polymer
A polymer (; Greek ''poly-'', "many" + '' -mer'', "part") is a substance or material consisting of very large molecules called macromolecules, composed of many repeating subunits. Due to their broad spectrum of properties, both synthetic and natural polymers play essential and ubiquitous roles in everyday life. Polymers range from familiar synthetic plastics such as polystyrene to natural biopolymers such as DNA and proteins that are fundamental to biological structure and function. Polymers, both natural and synthetic, are created via polymerization of many small molecules, known as monomers. Their consequently large molecular mass, relative to small molecule compounds, produces unique physical properties including toughness, high elasticity, viscoelasticity, and a tendency to form amorphous and semicrystalline structures rather than crystals. The term "polymer" derives from the Greek word πολύς (''polus'', meaning "many, much") and μέρος (''meros'', mean ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Syringe
A syringe is a simple reciprocating pump consisting of a plunger (though in modern syringes, it is actually a piston) that fits tightly within a cylindrical tube called a barrel. The plunger can be linearly pulled and pushed along the inside of the tube, allowing the syringe to take in and expel liquid or gas through a discharge orifice at the front (open) end of the tube. The open end of the syringe may be fitted with a hypodermic needle, a nozzle or tubing to direct the flow into and out of the barrel. Syringes are frequently used in clinical medicine to administer injections, infuse intravenous therapy into the bloodstream, apply compounds such as glue or lubricant, and draw/measure liquids. There are also prefilled syringes (disposable syringes marketed with liquid inside). The word "syringe" is derived from the Greek σύριγξ ('' syrinx'', meaning "Pan flute", "tube"). Medical syringes Sectors in the syringe and needle market include disposable and saf ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Mobile Phase
In analytical and organic chemistry, elution is the process of extracting one material from another by washing with a solvent; as in washing of loaded ion-exchange resins to remove captured ions. In a liquid chromatography experiment, for example, an analyte is generally adsorbed, or "bound to", an adsorbent in a liquid chromatography column. The adsorbent, a solid phase (stationary phase), is a powder which is coated onto a solid support. Based on an adsorbent's composition, it can have varying affinities to "hold" onto other molecules—forming a thin film on the surface of its particles. Elution then is the process of removing analytes from the adsorbent by running a solvent, called an "eluent", past the adsorbent/analyte complex. As the solvent molecules "elute", or travel down through the chromatography column, they can either pass by the adsorbent/analyte complex or they can displace the analyte by binding to the adsorbent in its place. After the solvent molecules displa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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96 Well Plate
A microplate, also known as a microtiter plate (''Microtiter'' is a registered trademark in the United States, therefore it should not be used generically without attribution), microwell plate or multiwell, is a flat plate with multiple "wells" used as small test tubes. The microplate has become a standard tool in analytical research and clinical diagnostic testing laboratories. A very common usage is in the enzyme-linked immunosorbent assay (ELISA), the basis of most modern medical diagnostic testing in humans and animals. A microplate typically has 6, 12, 24, 48, 96, 384 or 1536 sample wells arranged in a 2:3 rectangular matrix. Some microplates have been manufactured with 3456 or 9600 wells, and an "array tape" product has been developed that provides a continuous strip of microplates embossed on a flexible plastic tape. Each well of a microplate typically holds somewhere between tens of nanolitres to several millilitres of liquid. They can also be used to store dry powder ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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SPE Cartridges
SPE may refer to: Science and technology * Spe (planet), 14 Andromedae b * Serum protein electrophoresis * Solar particle event,generating very high energy protons * Solid phase extraction, from a mixture * Solid-phase epitaxy, from amorphous to crystalline * ''The Sound Pattern of English'', a 1968 book by Noam Chomsky and Morris Halle * Stanford prison experiment, in psychology * Synchronous payload envelope, in synchronous optical networking * SpE, abbreviation for Sporadic E propagation Computer science * Synergistic Processing Element in the Cell microprocessor * Signal-Processing Engine, for example in the PowerPC e500 * Single-Pair Ethernet Organizations * Sauber Petronas Engineering, car engine manufacturer * Societas Privata Europaea, a Europe-wide type of limited company * Sony Pictures Entertainment, a US company * SPE, later Luminus (company) * Special Police Establishment, later Central Bureau of Investigation, India * Special purpose entity, for a specific pur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |