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Soxhlet
A Soxhlet extractor is a piece of laboratory apparatus invented in 1879 by Franz von Soxhlet. It was originally designed for the extraction of a lipid from a solid material. Typically, Soxhlet extraction is used when the desired compound has a ''limited'' solubility in a solvent, and the impurity is insoluble in that solvent. It allows for unmonitored and unmanaged operation while efficiently recycling a small amount of solvent to dissolve a larger amount of material. Description A Soxhlet extractor has three main sections: a percolator (boiler and reflux) which circulates the solvent, a thimble (usually made of thick filter paper) which retains the solid to be extracted, and a siphon mechanism, which periodically empties the thimble. Assembly # The source material containing the compound to be extracted is placed inside the thimble. # The thimble is loaded into the main chamber of the Soxhlet extractor. # The extraction solvent to be used is placed in a distillation flask. # The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Soxhlet Extractor
A Soxhlet extractor is a piece of laboratory apparatus invented in 1879 by Franz von Soxhlet. It was originally designed for the extraction of a lipid from a solid material. Typically, Soxhlet extraction is used when the desired compound has a ''limited'' solubility in a solvent, and the impurity is insoluble in that solvent. It allows for unmonitored and unmanaged operation while efficiently recycling a small amount of solvent to dissolve a larger amount of material. Description A Soxhlet extractor has three main sections: a percolator (boiler and reflux) which circulates the solvent, a thimble (usually made of thick filter paper) which retains the solid to be extracted, and a siphon mechanism, which periodically empties the thimble. Assembly # The source material containing the compound to be extracted is placed inside the thimble. # The thimble is loaded into the main chamber of the Soxhlet extractor. # The extraction solvent to be used is placed in a distillation flask. # The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Soxhlet Mechanism
A Soxhlet extractor is a piece of laboratory apparatus invented in 1879 by Franz von Soxhlet. It was originally designed for the extraction of a lipid from a solid material. Typically, Soxhlet extraction is used when the desired compound has a ''limited'' solubility in a solvent, and the impurity is insoluble in that solvent. It allows for unmonitored and unmanaged operation while efficiently recycling a small amount of solvent to dissolve a larger amount of material. Description A Soxhlet extractor has three main sections: a percolator (boiler and reflux) which circulates the solvent, a thimble (usually made of thick filter paper) which retains the solid to be extracted, and a siphon mechanism, which periodically empties the thimble. Assembly # The source material containing the compound to be extracted is placed inside the thimble. # The thimble is loaded into the main chamber of the Soxhlet extractor. # The extraction solvent to be used is placed in a distillation flask. # The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Soxhlet Siphoning
A Soxhlet extractor is a piece of laboratory apparatus invented in 1879 by Franz von Soxhlet. It was originally designed for the extraction of a lipid from a solid material. Typically, Soxhlet extraction is used when the desired compound has a ''limited'' solubility in a solvent, and the impurity is insoluble in that solvent. It allows for unmonitored and unmanaged operation while efficiently recycling a small amount of solvent to dissolve a larger amount of material. Description A Soxhlet extractor has three main sections: a percolator (boiler and reflux) which circulates the solvent, a thimble (usually made of thick filter paper) which retains the solid to be extracted, and a siphon mechanism, which periodically empties the thimble. Assembly # The source material containing the compound to be extracted is placed inside the thimble. # The thimble is loaded into the main chamber of the Soxhlet extractor. # The extraction solvent to be used is placed in a distillation flask. # The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Soxhlet Extractor
A Soxhlet extractor is a piece of laboratory apparatus invented in 1879 by Franz von Soxhlet. It was originally designed for the extraction of a lipid from a solid material. Typically, Soxhlet extraction is used when the desired compound has a ''limited'' solubility in a solvent, and the impurity is insoluble in that solvent. It allows for unmonitored and unmanaged operation while efficiently recycling a small amount of solvent to dissolve a larger amount of material. Description A Soxhlet extractor has three main sections: a percolator (boiler and reflux) which circulates the solvent, a thimble (usually made of thick filter paper) which retains the solid to be extracted, and a siphon mechanism, which periodically empties the thimble. Assembly # The source material containing the compound to be extracted is placed inside the thimble. # The thimble is loaded into the main chamber of the Soxhlet extractor. # The extraction solvent to be used is placed in a distillation flask. # The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Franz Von Soxhlet
Franz Ritter von Soxhlet (January 12, 1848 Brno – May 5, 1926 Munich) was a German agricultural chemist from Brno. He invented the Soxhlet extractor in 1879 and in 1886 he proposed pasteurization be applied to milk and other beverages. Soxhlet is also known as the first scientist who fractionated the milk proteins in casein, albumin, globulin and lactoprotein. Furthermore, he described for the first time the sugar present in milk, lactose. The Soxhlet solution is an alternative to Fehling's solution for preparation of a comparable cupric/tartrate reagent to test for reducing sugars. He was the son of a Belgian immigrant. He gained a PhD at Leipzig in 1872. In 1879 he became a professor of agricultural chemistry at the Technical University of Munich The Technical University of Munich (TUM or TU Munich; german: Technische Universität München) is a public research university in Munich, Germany. It specializes in engineering, technology, medicine, and applied and natural scien ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Condenser (laboratory)
In chemistry, a condenser is laboratory apparatus used to condense vaporsthat is, turn them into liquidsby cooling them down. Condensers are routinely used in laboratory operations such as distillation, reflux, and extraction. In distillation, a mixture is heated until the more volatile components boil off, the vapors are condensed, and collected in a separate container. In reflux, a reaction involving volatile liquids is carried out at their boiling point, to speed it up; and the vapors that inevitably come off are condensed and returned to the reaction vessel. In Soxhlet extraction, a hot solvent is infused onto some powdered material, such as ground seeds, to leach out some poorly soluble component; the solvent is then automatically distilled out of the resulting solution, condensed, and infused again. Many different types of condensers have been developed for different applications and processing volumes. The simplest and oldest condenser is just a long tube through w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Condenser (laboratory)
In chemistry, a condenser is laboratory apparatus used to condense vaporsthat is, turn them into liquidsby cooling them down. Condensers are routinely used in laboratory operations such as distillation, reflux, and extraction. In distillation, a mixture is heated until the more volatile components boil off, the vapors are condensed, and collected in a separate container. In reflux, a reaction involving volatile liquids is carried out at their boiling point, to speed it up; and the vapors that inevitably come off are condensed and returned to the reaction vessel. In Soxhlet extraction, a hot solvent is infused onto some powdered material, such as ground seeds, to leach out some poorly soluble component; the solvent is then automatically distilled out of the resulting solution, condensed, and infused again. Many different types of condensers have been developed for different applications and processing volumes. The simplest and oldest condenser is just a long tube through w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pythagorean Cup
A Pythagorean cup (also known as a Pythagoras cup, Greedy Cup, Cup of Justice or Tantalus cup) is a practical joke device in a form of a drinking cup, credited to Pythagoras of Samos. When it is filled beyond a certain point, a siphoning effect causes the cup to drain its entire contents through the base. The cup can be used to learn about greed. Form and function A Pythagorean cup looks like a normal drinking cup, except that the bowl has a central column in it, giving it a shape like a Bundt pan. The central column of the bowl is positioned directly over the stem of the cup and over a hole at the bottom of the stem. A small open pipe runs from this hole almost to the top of the central column, where there is an open chamber. The chamber is connected by a second pipe to the bottom of the central column, where a hole in the column exposes the pipe to (the contents of) the bowl of the cup. When the cup is filled, liquid rises through the second pipe up to the chamber at the t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Piperine
Piperine, along with its isomer chavicine, is the alkaloid responsible for the pungency of black pepper and long pepper. It has been used in some forms of traditional medicine. Preparation Due to its poor solubility in water, piperine is typically extracted from black pepper by using organic solvents like dichloromethane. The amount of piperine varies from 1–2% in long pepper, to 5–10% in commercial white and black peppers. Piperine can also be prepared by treating a concentrated alcoholic extract of black pepper with an alcoholic solution of potassium hydroxide to remove resin (said to contain chavicine, an isomer of piperine). The solution is decanted from the insoluble residue and left to stand overnight. During this period, the alkaloid slowly crystallizes from the solution. Piperine has been synthesized by the action of piperonoyl chloride on piperidine. Reactions Piperine forms salts only with strong acids. The platinichloride B4·H2PtCl6 forms orange-red needles ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metrologia
''Metrologia'' is a bimonthly journal dealing with the scientific aspects of metrology. It has been running since 1965 and has been published by the International Bureau of Weights and Measures since 1991. Since 2003 the journal has been published by IOP Publishing on behalf of the bureau. The journal covers the fundamentals of measurements, in particular those dealing with the seven base units of the International System of Units (metre, kilogram, second, ampere, kelvin, candela, mole) or proposals to replace them. The editors-in-chief are Sten Bergstrand (RISE Research Institutes of Sweden) and Janet Miles (International Bureau of Weights and Measures). Abstracting and indexing This journal is indexed by the following databases: *Science Citation Index Expanded *Scopus * Inspec *Chemical Abstracts Service *Compendex *GeoRef *MathSciNet *Astrophysics Data System *VINITI Abstracts Journal VINITI Database RAS is a database provided by the All-Russian Institute for Scientif ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Standard (metrology)
In metrology (the science of measurement), a standard (or etalon) is an object, system, or experiment that bears a defined relationship to a unit of measurement of a physical quantity. Standards are the fundamental reference for a system of weights and measures, against which all other measuring devices are compared. Historical standards for length, volume, and mass were defined by many different authorities, which resulted in confusion and inaccuracy of measurements. Modern measurements are defined in relationship to internationally standardized reference objects, which are used under carefully controlled laboratory conditions to define the units of length, mass, electrical potential, and other physical quantities. Hierarchy of standards There is a three-level hierarchy of physical measurement standards. At the top of the tree are the master standards – these are known as ''primary standards''. Primary standards are made to the highest metrological quality and are the definit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anselme Payen
Anselme Payen (; 6 January 1795 – 12 May 1871) was a French chemist known for discovering the enzyme diastase, and the carbohydrate cellulose. Biography Payen was born in Paris. He began studying science with his father when he was a 13-year-old, and later studied Chemistry at the École Polytechnique under the chemists Louis Nicolas Vauquelin and Michel Eugène Chevreul. At the age of 23, Payen became manager of a borax-refining factory, where he developed a process for synthesizing borax from soda and boric acid. Previously, all borax had been imported from the East Indies exclusively by the Dutch. Payen's new method of synthesizing borax allowed him to sell the mineral at one third the going price, and break the Dutch monopoly. Payen also developed processes for refining sugar, along with a way to refine starch and alcohol from potatoes, and a method for determination of nitrogen. Payen invented a decolorimeter, which dealt with the analysis, decolorization, bleaching, a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
