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)
Compounds in which a methyl group is attached to the cyano moiety.
Liquid chromatographic techniques which feature high inlet pressures, high sensitivity, and high speed.
Chromatographic techniques in which the mobile phase is a liquid.
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.
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.
A colorless liquid used as a solvent and an antiseptic. It is one of the ketone bodies produced during ketoacidosis.
Concentration or quantity that is derived from the smallest measure that can be detected with reasonable certainty for a given analytical procedure.
Determination, by measurement or comparison with a standard, of the correct value of each scale reading on a meter or other measuring instrument; or determination of the settings of a control device that correspond to particular values of voltage, current, frequency or other output.
Determination of the spectra of ultraviolet absorption by specific molecules in gases or liquids, for example Cl2, SO2, NO2, CS2, ozone, mercury vapor, and various unsaturated compounds. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
A basis of value established for the measure of quantity, weight, extent or quality, e.g. weight standards, standard solutions, methods, techniques, and procedures used in diagnosis and therapy.
The chemical and physical integrity of a pharmaceutical product.
The statistical reproducibility of measurements (often in a clinical context), including the testing of instrumentation or techniques to obtain reproducible results. The concept includes reproducibility of physiological measurements, which may be used to develop rules to assess probability or prognosis, or response to a stimulus; reproducibility of occurrence of a condition; and reproducibility of experimental results.
A mass spectrometry technique using two (MS/MS) or more mass analyzers. With two in tandem, the precursor ions are mass-selected by a first mass analyzer, and focused into a collision region where they are then fragmented into product ions which are then characterized by a second mass analyzer. A variety of techniques are used to separate the compounds, ionize them, and introduce them to the first mass analyzer. For example, for in GC-MS/MS, GAS CHROMATOGRAPHY-MASS SPECTROMETRY is involved in separating relatively small compounds by GAS CHROMATOGRAPHY prior to injecting them into an ionization chamber for the mass selection.
A mass spectrometry technique used for analysis of nonvolatile compounds such as proteins and macromolecules. The technique involves preparing electrically charged droplets from analyte molecules dissolved in solvent. The electrically charged droplets enter a vacuum chamber where the solvent is evaporated. Evaporation of solvent reduces the droplet size, thereby increasing the coulombic repulsion within the droplet. As the charged droplets get smaller, the excess charge within them causes them to disintegrate and release analyte molecules. The volatilized analyte molecules are then analyzed by mass spectrometry.
A clear, odorless, tasteless liquid that is essential for most animal and plant life and is an excellent solvent for many substances. The chemical formula is hydrogen oxide (H2O). (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
An extraction method that separates analytes using a solid phase and a liquid phase. It is used for preparative sample cleanup before analysis by CHROMATOGRAPHY and other analytical methods.
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)
The location of the atoms, groups or ions relative to one another in a molecule, as well as the number, type and location of covalent bonds.
An analytical method used in determining the identity of a chemical based on its mass using mass analyzers/mass spectrometers.
Binary classification measures to assess test results. Sensitivity or recall rate is the proportion of true positives. Specificity is the probability of correctly determining the absence of a condition. (From Last, Dictionary of Epidemiology, 2d ed)
A colorless liquid made by oxidation of aliphatic hydrocarbons that is used as a solvent and chemical intermediate.
The removal of a soluble component from a liquid mixture by contact with a second liquid, immiscible with the carrier liquid, in which the component is preferentially soluble. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)
The study of the structure, preparation, properties, and reactions of carbon compounds. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)
An isomer of 1-PROPANOL. It is a colorless liquid having disinfectant properties. It is used in the manufacture of acetone and its derivatives and as a solvent. Topically, it is used as an antiseptic.
Methodologies used for the isolation, identification, detection, and quantitation of chemical substances.
Drugs used by veterinarians in the treatment of animal diseases. The veterinarian's pharmacological armamentarium is the counterpart of drugs treating human diseases, with dosage and administration adjusted to the size, weight, disease, and idiosyncrasies of the species. In the United States most drugs are subject to federal regulations with special reference to the safety of drugs and residues in edible animal products.
The normality of a solution with respect to HYDROGEN ions; H+. It is related to acidity measurements in most cases by pH = log 1/2[1/(H+)], where (H+) is the hydrogen ion concentration in gram equivalents per liter of solution. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)
The homogeneous mixtures formed by the mixing of a solid, liquid, or gaseous substance (solute) with a liquid (the solvent), from which the dissolved substances can be recovered by physical processes. (From Grant & Hackh's Chemical Dictionary, 5th ed)
A highly polar organic liquid, that is used widely as a chemical solvent. Because of its ability to penetrate biological membranes, it is used as a vehicle for topical application of pharmaceuticals. It is also used to protect tissue during CRYOPRESERVATION. Dimethyl sulfoxide shows a range of pharmacological activity including analgesia and anti-inflammation.
A chlorinated hydrocarbon that has been used as an inhalation anesthetic and acts as a narcotic in high concentrations. Its primary use is as a solvent in manufacturing and food technology.
Salts that melt below 100 C. Their low VOLATILIZATION can be an advantage over volatile organic solvents.
Models used experimentally or theoretically to study molecular shape, electronic properties, or interactions; includes analogous molecules, computer-generated graphics, and mechanical structures.
The reactions and interactions of atoms and molecules, the changes in their structure and composition, and associated energy changes.
Drugs and their metabolites which are found in the edible tissues and milk of animals after their medication with specific drugs. This term can also apply to drugs found in adipose tissue of humans after drug treatment.
The study of chemical changes resulting from electrical action and electrical activity resulting from chemical changes.
A highly-sensitive (in the picomolar range, which is 10,000-fold more sensitive than conventional electrophoresis) and efficient technique that allows separation of PROTEINS; NUCLEIC ACIDS; and CARBOHYDRATES. (Segen, Dictionary of Modern Medicine, 1992)
A microanalytical technique combining mass spectrometry and gas chromatography for the qualitative as well as quantitative determinations of compounds.
Six-carbon saturated hydrocarbon group of the methane series. Include isomers and derivatives. Various polyneuropathies are caused by hexane poisoning.
Inorganic or organic compounds derived from phosphine (PH3) by the replacement of H atoms. (From Grant & Hackh's Chemical Dictionary, 5th ed)
A chemical system that functions to control the levels of specific ions in solution. When the level of hydrogen ion in solution is controlled the system is called a pH buffer.
A broad class of substances containing carbon and its derivatives. Many of these chemicals will frequently contain hydrogen with or without oxygen, nitrogen, sulfur, phosphorus, and other elements. They exist in either carbon chain or carbon ring form.
Spectroscopic method of measuring the magnetic moment of elementary particles such as atomic nuclei, protons or electrons. It is employed in clinical applications such as NMR Tomography (MAGNETIC RESONANCE IMAGING).
A separation technique which combines LIQUID CHROMATOGRAPHY and CAPILLARY ELECTROPHORESIS.
A phenethylamine that is an isomer of EPHEDRINE which has less central nervous system effects and usage is mainly for respiratory tract decongestion.
The presence of organisms, or any foreign material that makes a drug preparation impure.
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)
Pyrolysis of organic compounds at the temperature of a hydrogen-air flame to produce ionic intermediates which can be collected and the resulting ion current measured by gas chromatography.
Alkyl compounds containing a hydroxyl group. They are classified according to relation of the carbon atom: primary alcohols, R-CH2OH; secondary alcohols, R2-CHOH; tertiary alcohols, R3-COH. (From Grant & Hackh's Chemical Dictionary, 5th ed)
A rigorously mathematical analysis of energy relationships (heat, work, temperature, and equilibrium). It describes systems whose states are determined by thermal parameters, such as temperature, in addition to mechanical and electromagnetic parameters. (From Hawley's Condensed Chemical Dictionary, 12th ed)
The phenomenon whereby compounds whose molecules have the same number and kind of atoms and the same atomic arrangement, but differ in their spatial relationships. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 5th ed)
Completed forms of the pharmaceutical preparation in which prescribed doses of medication are included. They are designed to resist action by gastric fluids, prevent vomiting and nausea, reduce or alleviate the undesirable taste and smells associated with oral administration, achieve a high concentration of drug at target site, or produce a delayed or long-acting drug effect.
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.
An anticonvulsant especially useful in the treatment of absence seizures unaccompanied by other types of seizures.
The application of medical knowledge to questions of law.
Theoretical representations that simulate the behavior or activity of chemical processes or phenomena; includes the use of mathematical equations, computers, and other electronic equipment.
A centrally acting skeletal muscle relaxant whose mechanism of action is not completely understood but may be related to its sedative actions. It is used as an adjunct in the symptomatic treatment of musculoskeletal conditions associated with painful muscle spasm. (From Martindale, The Extra Pharmacopoeia, 30th ed, p1202)
The characteristic 3-dimensional shape of a protein, including the secondary, supersecondary (motifs), tertiary (domains) and quaternary structure of the peptide chain. PROTEIN STRUCTURE, QUATERNARY describes the conformation assumed by multimeric proteins (aggregates of more than one polypeptide chain).
Pesticides or their breakdown products remaining in the environment following their normal use or accidental contamination.
Chemical reactions effected by light.
Solid dosage forms, of varying weight, size, and shape, which may be molded or compressed, and which contain a medicinal substance in pure or diluted form. (Dorland, 28th ed)
An antiepileptic agent related to the barbiturates; it is partly metabolized to PHENOBARBITAL in the body and owes some of its actions to this metabolite. Adverse effects are reported to be more frequent than with PHENOBARBITAL. (From Martindale, The Extra Pharmacopoeia, 30th ed, p309)
The pressure at any point in an atmosphere due solely to the weight of the atmospheric gases above the point concerned.
Phenolic metacyclophanes derived from condensation of PHENOLS and ALDEHYDES. The name derives from the vase-like molecular structures. A bracketed [n] indicates the number of aromatic rings.
Detection of drugs that have been abused, overused, or misused, including legal and illegal drugs. Urine screening is the usual method of detection.
A system for verifying and maintaining a desired level of quality in a product or process by careful planning, use of proper equipment, continued inspection, and corrective action as required. (Random House Unabridged Dictionary, 2d ed)
A widely used industrial solvent.
The facilitation of a chemical reaction by material (catalyst) that is not consumed by the reaction.
The study of crystal structure using X-RAY DIFFRACTION techniques. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
The rate dynamics in chemical or physical systems.
Field of chemistry pertaining to the study of inorganic compounds or ions and their interactions with biological ligands at the molecular level.
Measurement of the intensity and quality of fluorescence.
Use of various chemical separation and extraction methods, such as SOLID PHASE EXTRACTION; CHROMATOGRAPHY; and SUPERCRITICAL FLUID EXTRACTION; to prepare samples for analytical measurement of components.
The ability of a substance to be dissolved, i.e. to form a solution with another substance. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)
The development and use of techniques and equipment to study or perform chemical reactions, with small quantities of materials, frequently less than a milligram or a milliliter.
A hybrid separation technique combining both chromatographic and electrophoretic separation principles. While the method was invented to separate neutral species, it can also be applied to charged molecules such as small peptides.
Derivatives of ACETIC ACID. Included under this heading are a broad variety of acid forms, salts, esters, and amides that contain the carboxymethane structure.
Neutral or negatively charged ligands bonded to metal cations or neutral atoms. The number of ligand atoms to which the metal center is directly bonded is the metal cation's coordination number, and this number is always greater than the regular valence or oxidation number of the metal. A coordination complex can be negative, neutral, or positively charged.
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.
A low-energy attractive force between hydrogen and another element. It plays a major role in determining the properties of water, proteins, and other compounds.
A condition or physical state produced by the ingestion, injection, inhalation of or exposure to a deleterious agent.
A thiazide diuretic with actions and uses similar to those of HYDROCHLOROTHIAZIDE. It has been used in the treatment of familial hyperkalemia, hypertension, edema, and urinary tract disorders. (From Martindale, The Extra Pharmacopoeia, 30th ed, p810)
Chemistry dealing with the composition and preparation of agents having PHARMACOLOGIC ACTIONS or diagnostic use.
The characteristic three-dimensional shape of a molecule.
Inorganic salts of HYDROGEN CYANIDE containing the -CN radical. The concept also includes isocyanides. It is distinguished from NITRILES, which denotes organic compounds containing the -CN radical.
Animal reproductive bodies, or the contents thereof, used as food. The concept is differentiated from OVUM, the anatomic or physiologic entity.
A phenomenon in which the surface of a liquid where it contacts a solid is elevated or depressed, because of the relative attraction of the molecules of the liquid for each other and for those of the solid. (from McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
The phenomenon whereby certain chemical compounds have structures that are different although the compounds possess the same elemental composition. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 5th ed)
A colorless liquid with a sharp burning taste and slight odor. It is used as a local anesthetic and to reduce pain associated with LIDOCAINE injection. Also, it is used in the manufacture of other benzyl compounds, as a pharmaceutic aid, and in perfumery and flavoring.
Drugs intended for human or veterinary use, presented in their finished dosage form. Included here are materials used in the preparation and/or formulation of the finished dosage form.
The dissociation of molecules in the air into positive and negative ions under the influence of an electric field.
A hard, brittle, grayish-white rare earth metal with an atomic symbol Ru, atomic number 44, and atomic weight 101.07. It is used as a catalyst and hardener for PLATINUM and PALLADIUM.
A chemical reaction in which an electron is transferred from one molecule to another. The electron-donating molecule is the reducing agent or reductant; the electron-accepting molecule is the oxidizing agent or oxidant. Reducing and oxidizing agents function as conjugate reductant-oxidant pairs or redox pairs (Lehninger, Principles of Biochemistry, 1982, p471).
A group of compounds that are derivatives of methoxybenzene and contain the general formula R-C7H7O.
Chlorinated ethanes which are used extensively as industrial solvents. They have been utilized in numerous home-use products including spot remover preparations and inhalant decongestant sprays. These compounds cause central nervous system and cardiovascular depression and are hepatotoxic. Include 1,1,1- and 1,1,2-isomers.
Inorganic compounds that contain potassium as an integral part of the molecule.
Colorless, odorless crystals that are used extensively in research laboratories for the preparation of polyacrylamide gels for electrophoresis and in organic synthesis, and polymerization. Some of its polymers are used in sewage and wastewater treatment, permanent press fabrics, and as soil conditioning agents.
Statistical models in which the value of a parameter for a given value of a factor is assumed to be equal to a + bx, where a and b are constants. The models predict a linear regression.
Concentrated pharmaceutical preparations of plants obtained by removing active constituents with a suitable solvent, which is evaporated away, and adjusting the residue to a prescribed standard.
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)
A reagent used for the determination of iron.
Derivatives of formic acids. Included under this heading are a broad variety of acid forms, salts, esters, and amides that are formed with a single carbon carboxy group.
The application of TOXICOLOGY knowledge to questions of law.
A group of compounds derived from ammonia by substituting organic radicals for the hydrogens. (From Grant & Hackh's Chemical Dictionary, 5th ed)
The formation of a solid in a solution as a result of a chemical reaction or the aggregation of soluble substances into complexes large enough to fall out of solution.
Compounds similar to hydrocarbons in which a tetravalent silicon atom replaces the carbon atom. They are very reactive, ignite in air, and form useful derivatives.
The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.
Compounds with a 5-membered ring of four carbons and an oxygen. They are aromatic heterocycles. The reduced form is tetrahydrofuran.
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.
Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.
Compounds that contain the Cl(=O)(=O)(=O)O- structure. Included under this heading is perchloric acid and the salts and ester forms of perchlorate.
Organic compounds that include a cyclic ether with three ring atoms in their structure. They are commonly used as precursors for POLYMERS such as EPOXY RESINS.
A type of glycoside widely distributed in plants. Each consists of a sapogenin as the aglycone moiety, and a sugar. The sapogenin may be a steroid or a triterpene and the sugar may be glucose, galactose, a pentose, or a methylpentose.
A commonly used laboratory solvent. It was previously used as an anesthetic, but was banned from use in the U.S. due to its suspected carcinogenicity.
Organic compounds containing the -CN radical. The concept is distinguished from CYANIDES, which denotes inorganic salts of HYDROGEN CYANIDE.
A clear, colorless liquid rapidly absorbed from the gastrointestinal tract and distributed throughout the body. It has bactericidal activity and is used often as a topical disinfectant. It is widely used as a solvent and preservative in pharmaceutical preparations as well as serving as the primary ingredient in ALCOHOLIC BEVERAGES.
A family of SERINE ENDOPEPTIDASES isolated from Bacillus subtilis. EC 3.4.21.-
The process of cleaving a chemical compound by the addition of a molecule of water.
An element of the rare earth family of metals. It has the atomic symbol Ce, atomic number 58, and atomic weight 140.12. Cerium is a malleable metal used in industrial applications.
The level of protein structure in which regular hydrogen-bond interactions within contiguous stretches of polypeptide chain give rise to alpha helices, beta strands (which align to form beta sheets) or other types of coils. This is the first folding level of protein conformation.
Chemical compounds which yield hydrogen ions or protons when dissolved in water, whose hydrogen can be replaced by metals or basic radicals, or which react with bases to form salts and water (neutralization). An extension of the term includes substances dissolved in media other than water. (Grant & Hackh's Chemical Dictionary, 5th ed)
A change from planar to elliptic polarization when an initially plane-polarized light wave traverses an optically active medium. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
Measurement and evaluation of the components of substances to be taken as FOOD.
Members of the class of compounds composed of AMINO ACIDS joined together by peptide bonds between adjacent amino acids into linear, branched or cyclical structures. OLIGOPEPTIDES are composed of approximately 2-12 amino acids. Polypeptides are composed of approximately 13 or more amino acids. PROTEINS are linear polypeptides that are normally synthesized on RIBOSOMES.
Benzopyrroles with the nitrogen at the number one carbon adjacent to the benzyl portion, in contrast to ISOINDOLES which have the nitrogen away from the six-membered ring.
A class of compounds of the type R-M, where a C atom is joined directly to any other element except H, C, N, O, F, Cl, Br, I, or At. (Grant & Hackh's Chemical Dictionary, 5th ed)
A highly caustic substance that is used to neutralize acids and make sodium salts. (From Merck Index, 11th ed)
A principle of estimation in which the estimates of a set of parameters in a statistical model are those quantities minimizing the sum of squared differences between the observed values of a dependent variable and the values predicted by the model.
Elements of limited time intervals, contributing to particular results or situations.
Derivatives of acetamide that are used as solvents, as mild irritants, and in organic synthesis.
Stable elementary particles having the smallest known positive charge, found in the nuclei of all elements. The proton mass is less than that of a neutron. A proton is the nucleus of the light hydrogen atom, i.e., the hydrogen ion.
A widely used anti-inflammatory agent isolated from the licorice root. It is metabolized to GLYCYRRHETINIC ACID, which inhibits 11-BETA-HYDROXYSTEROID DEHYDROGENASES and other enzymes involved in the metabolism of CORTICOSTEROIDS. Therefore, glycyrrhizic acid, which is the main and sweet component of licorice, has been investigated for its ability to cause hypermineralocorticoidism with sodium retention and potassium loss, edema, increased blood pressure, as well as depression of the renin-angiotensin-aldosterone system.
Placing of a hydroxyl group on a compound in a position where one did not exist before. (Stedman, 26th ed)
Electric conductors through which electric currents enter or leave a medium, whether it be an electrolytic solution, solid, molten mass, gas, or vacuum.
An anticonvulsant that is used to treat a wide variety of seizures. It is also an anti-arrhythmic and a muscle relaxant. The mechanism of therapeutic action is not clear, although several cellular actions have been described including effects on ion channels, active transport, and general membrane stabilization. The mechanism of its muscle relaxant effect appears to involve a reduction in the sensitivity of muscle spindles to stretch. Phenytoin has been proposed for several other therapeutic uses, but its use has been limited by its many adverse effects and interactions with other drugs.
The exposure to potentially harmful chemical, physical, or biological agents that occurs as a result of one's occupation.
Compounds formed by the joining of smaller, usually repeating, units linked by covalent bonds. These compounds often form large macromolecules (e.g., BIOPOLYMERS; PLASTICS).
Acetic acid derivatives of the heterocyclic compound indole. (Merck Index, 11th ed)
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.
A family of isomeric, colorless aromatic hydrocarbon liquids, that contain the general formula C6H4(CH3)2. They are produced by the destructive distillation of coal or by the catalytic reforming of petroleum naphthenic fractions. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 5th ed)
An atom or group of atoms that have a positive or negative electric charge due to a gain (negative charge) or loss (positive charge) of one or more electrons. Atoms with a positive charge are known as CATIONS; those with a negative charge are ANIONS.
A histamine H1 antagonist used in allergic reactions, hay fever, rhinitis, urticaria, and asthma. It has also been used in veterinary applications. One of the most widely used of the classical antihistaminics, it generally causes less drowsiness and sedation than PROMETHAZINE.
A group of 3-hydroxy-4-keto-FLAVONOIDS.
A chlorinated hydrocarbon used as an industrial solvent and cooling liquid in electrical transformers. It is a potential carcinogen.
Synthetic or naturally occurring substances related to coumarin, the delta-lactone of coumarinic acid.
Accidental or deliberate use of a medication or street drug in excess of normal dosage.
Organic compounds containing the -CO-NH2 radical. Amides are derived from acids by replacement of -OH by -NH2 or from ammonia by the replacement of H by an acyl group. (From Grant & Hackh's Chemical Dictionary, 5th ed)
The parts of a macromolecule that directly participate in its specific combination with another molecule.
Organic compounds containing the carboxy group (-COOH). This group of compounds includes amino acids and fatty acids. Carboxylic acids can be saturated, unsaturated, or aromatic.
The measurement of the amplitude of the components of a complex waveform throughout the frequency range of the waveform. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)
A highly volatile inhalation anesthetic used mainly in short surgical procedures where light anesthesia with good analgesia is required. It is also used as an industrial solvent. Prolonged exposure to high concentrations of the vapor can lead to cardiotoxicity and neurological impairment.
A liver microsomal cytochrome P450 enzyme that catalyzes the 16-alpha-hydroxylation of a broad spectrum of steroids, fatty acids, and xenobiotics in the presence of molecular oxygen and NADPH-FERRIHEMOPROTEIN REDUCTASE. This enzyme is encoded by a number of genes from several CYP2 subfamilies.
Organic compounds that generally contain an amino (-NH2) and a carboxyl (-COOH) group. Twenty alpha-amino acids are the subunits which are polymerized to form proteins.
Any compound that contains a constituent sugar, in which the hydroxyl group attached to the first carbon is substituted by an alcoholic, phenolic, or other group. They are named specifically for the sugar contained, such as glucoside (glucose), pentoside (pentose), fructoside (fructose), etc. Upon hydrolysis, a sugar and nonsugar component (aglycone) are formed. (From Dorland, 28th ed; From Miall's Dictionary of Chemistry, 5th ed)
A superfamily of hundreds of closely related HEMEPROTEINS found throughout the phylogenetic spectrum, from animals, plants, fungi, to bacteria. They include numerous complex monooxygenases (MIXED FUNCTION OXYGENASES). In animals, these P-450 enzymes serve two major functions: (1) biosynthesis of steroids, fatty acids, and bile acids; (2) metabolism of endogenous and a wide variety of exogenous substrates, such as toxins and drugs (BIOTRANSFORMATION). They are classified, according to their sequence similarities rather than functions, into CYP gene families (>40% homology) and subfamilies (>59% homology). For example, enzymes from the CYP1, CYP2, and CYP3 gene families are responsible for most drug metabolism.
The formation of crystalline substances from solutions or melts. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
Organic compounds containing a carbonyl group in the form -CHO.
Organic compounds that contain phosphorus as an integral part of the molecule. Included under this heading is broad array of synthetic compounds that are used as PESTICIDES and DRUGS.
Chinese herbal or plant extracts which are used as drugs to treat diseases or promote general well-being. The concept does not include synthesized compounds manufactured in China.
Chemical bond cleavage reactions resulting from absorption of radiant energy.
Domesticated bovine animals of the genus Bos, usually kept on a farm or ranch and used for the production of meat or dairy products or for heavy labor.
A sulphonylurea hypoglycemic agent with actions and uses similar to those of CHLORPROPAMIDE. (From Martindale, The Extra Pharmacopoeia, 30th ed, p290)
Eight-carbon saturated hydrocarbon group of the methane series. Include isomers and derivatives.
Benzene derivatives that include one or more hydroxyl groups attached to the ring structure.
An ethylene compound with two hydroxy groups (-OH) located on adjacent carbons. They are viscous and colorless liquids. Some are used as anesthetics or hypnotics. However, the class is best known for their use as a coolant or antifreeze.
Isomeric forms and derivatives of butanol (C4H9OH).
Heterocyclic compounds of a ring with SULFUR and two NITROGEN atoms fused to a BENZENE ring. Members inhibit SODIUM-POTASSIUM-CHLORIDE SYMPORTERS and are used as DIURETICS.
Classic quantitative assay for detection of antigen-antibody reactions using a radioactively labeled substance (radioligand) either directly or indirectly to measure the binding of the unlabeled substance to a specific antibody or other receptor system. Non-immunogenic substances (e.g., haptens) can be measured if coupled to larger carrier proteins (e.g., bovine gamma-globulin or human serum albumin) capable of inducing antibody formation.
Inorganic or organic compounds that contain divalent iron.
A method of separation of two or more substances by repeated distribution between two immiscible liquid phases that move past each other in opposite directions. It is a form of liquid-liquid chromatography. (Stedman, 25th ed)
A phase transition from liquid state to gas state, which is affected by Raoult's law. It can be accomplished by fractional distillation.
Hydroxycinnamic acid and its derivatives. Act as activators of the indoleacetic acid oxidizing system, thereby producing a decrease in the endogenous level of bound indoleacetic acid in plants.
Closed vesicles of fragmented endoplasmic reticulum created when liver cells or tissue are disrupted by homogenization. They may be smooth or rough.
Purine or pyrimidine bases attached to a ribose or deoxyribose. (From King & Stansfield, A Dictionary of Genetics, 4th ed)
A filament-like structure consisting of a shaft which projects to the surface of the SKIN from a root which is softer than the shaft and lodges in the cavity of a HAIR FOLLICLE. It is found on most surfaces of the body.
Hormonally active polypeptides that can induce the transformed phenotype when added to normal, non-transformed cells. They have been found in culture fluids from retrovirally transformed cells and in tumor-derived cells as well as in non-neoplastic sources. Their transforming activities are due to the simultaneous action of two otherwise unrelated factors, TRANSFORMING GROWTH FACTOR ALPHA and TRANSFORMING GROWTH FACTOR BETA.
The process of observing, recording, or detecting the effects of a chemical substance administered to an individual therapeutically or diagnostically.
A series of steps taken in order to conduct research.
A characteristic feature of enzyme activity in relation to the kind of substrate on which the enzyme or catalytic molecule reacts.
A system of traditional medicine which is based on the beliefs and practices of the Chinese culture.
A molecule that binds to another molecule, used especially to refer to a small molecule that binds specifically to a larger molecule, e.g., an antigen binding to an antibody, a hormone or neurotransmitter binding to a receptor, or a substrate or allosteric effector binding to an enzyme. Ligands are also molecules that donate or accept a pair of electrons to form a coordinate covalent bond with the central metal atom of a coordination complex. (From Dorland, 27th ed)
A mass spectrometric technique that is used for the analysis of large biomolecules. Analyte molecules are embedded in an excess matrix of small organic molecules that show a high resonant absorption at the laser wavelength used. The matrix absorbs the laser energy, thus inducing a soft disintegration of the sample-matrix mixture into free (gas phase) matrix and analyte molecules and molecular ions. In general, only molecular ions of the analyte molecules are produced, and almost no fragmentation occurs. This makes the method well suited for molecular weight determinations and mixture analysis.
An analytical method for detecting and measuring FLUORESCENCE in compounds or targets such as cells, proteins, or nucleotides, or targets previously labeled with FLUORESCENCE AGENTS.
Liquids that are suitable for drinking. (From Merriam Webster Collegiate Dictionary, 10th ed)
Analgesic antipyretic derivative of acetanilide. It has weak anti-inflammatory properties and is used as a common analgesic, but may cause liver, blood cell, and kidney damage.
Deuterium. The stable isotope of hydrogen. It has one neutron and one proton in the nucleus.
A computer simulation developed to study the motion of molecules over a period of time.
Computer-based representation of physical systems and phenomena such as chemical processes.
Derivatives of carbamic acid, H2NC(=O)OH. Included under this heading are N-substituted and O-substituted carbamic acids. In general carbamate esters are referred to as urethanes, and polymers that include repeating units of carbamate are referred to as POLYURETHANES. Note however that polyurethanes are derived from the polymerization of ISOCYANATES and the singular term URETHANE refers to the ethyl ester of carbamic acid.
... acetonitrile, and dimethyl sulfoxide. Polar solvents are often found to have a high dielectric constant, although other solvent ... Polar solvents can be used to dissolve inorganic or ionic compounds such as salts. The conductivity of a solution depends on ... as solvent ordering increases and solvent-solvent interactions decrease. Stronger interactions among solvent molecules leads to ... Solvents that can donate H-bonds are referred to as protic, while solvents that do not contain a polarized bond to a hydrogen ...
... be nitrated with sodium nitrate and acidic ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate in acetonitrile solvent ... Tajik, H.; Niknam, K.; Parsa, F. (2009). "Using acidic ionic liquid 1-butyl-3-methylimidazolium hydrogen sulfate in selective ...
... organic solvent (mostly acetonitrile). The hydrophobic interactions between protein and CBB are reduced by the organic fraction ... At the same time, the ionic part of the solution diminishes the electrostatic bonds between the dye and the positively charged ... In contrast to a mixture of water with organic solvent the effectivity of destaining is increased. An increase of temperature ... Many protocols contain an additional fraction of acetonitrile to the extraction solution which, in concentrations above 30% (v/ ...
With surface chemistries that are weakly ionic, the choice of pH can affect the ionic nature of the column chemistry. Properly ... However, any aprotic solvent miscible with water (e.g. THF or dioxane) can be used. Alcohols can also be used, however, their ... 70%-90% acetonitrile), can be used to increase the mobile phase polarity to affect elution. These salts are not volatile, so ... opposite charged ionic, or non-ionic) functional groups of the analyte(s). For example, one could use a cation exchange ( ...
In polar solvents such as acetonitrile, Ph3PCl2 adopts an ionic phosphonium salt structure, [Ph3PCl+]Cl−, whereas in non-polar ... Two [Ph3PCl+] species can also adopt an unusual dinuclear ionic structure-both interacting with a Cl− via long Cl-Cl contacts. ... "Structural dependence of the reagent Ph3PCl2 on the nature of the solvent, both in the solid state and in solution; X-ray ... Cl but an unusual dinuclear ionic species, [Ph3PCl+⋯Cl-⋯+CIPPH3]Cl containing long Cl-Cl contacts". Chemical Communications (22 ...
In solvents with donor properties such as acetonitrile, CH3CN ionic complexes are formed which make the solution conducting: ...
The pressurized liquid is typically a mixture of solvents (e.g., water, acetonitrile and/or methanol) and is referred to as a " ... These interactions are physical in nature, such as hydrophobic (dispersive), dipole-dipole and ionic, most often a combination ... The retention can be decreased by adding a less polar solvent (methanol, acetonitrile) into the mobile phase to reduce the ... In reversed-phase chromatography, solvent A is often water or an aqueous buffer, while B is an organic solvent miscible with ...
... was first prepared in 1847 by the French chemist Jean-Baptiste Dumas. Acetonitrile is used mainly as a solvent in ... With a dipole moment of 3.92 D, acetonitrile dissolves a wide range of ionic and nonpolar compounds and is useful as a mobile ... Industrially, it is used as a solvent for the manufacture of pharmaceuticals and photographic film. Acetonitrile is a common ... Lowe, Derek (2009). "The Great Acetonitrile Shortage". Science Translational Medicine. A. Tullo (2008). "A Solvent Dries Up". ...
... acidic ionic liquid as an efficient and reusable catalyst for one-pot synthesis of 1-amidoalkyl 2-naphthols under solvent-free ... 4-butanesultone with triethylamine in acetonitrile to the zwitterion (85% yield) and subsequent reaction with concentrated ... The ionic liquid 4-triethylammonium butane-1-sulfonic acid hydrogensulfate (TEBSA HSO4) is formed by the reaction of 1, ... The ring opening of 1,4-butanesultone with organic chloride salts yields ionic liquids of the 4-chlorobutylsulfonate type in ...
Palladium chloride is insoluble in most organic solvents, but it forms soluble monomeric units with acetonitrile and ... Some, such as sodium chloride are ionic, while others are covalently bonded. Covalently bonded metal halides may be discrete ... V. Gutmann (1976). "Solvent effects on the reactivities of organometallic compounds". Coord. Chem. Rev. 18 (2): 225-255. doi: ... They are usually insoluble in water, but soluble in organic solvent. Polymeric metal halides generally have melting and boiling ...
... reference for nonaqueous work as it turns out the platinum is rapidly poisoned by many solvents including acetonitrile[citation ... and unmeasurable junction potentials to the cell in the form of a liquid-liquid junction as well as different ionic composition ... Much as pKa are related between solvents, but not the same, so is the case with E°. While the SHE might seem to be a reasonable ... Solvent E1/2 (FeCp20/+ vs SCE, 0.1 M NBu4PF6 at 298 K) ... While it is convenient to compare between solvents to ...
For example, in acetonitrile both contact and solvent-shared ion pairs of Li(NCS) have been observed. In methanol the 2:1 ... Goralski, P.; Chabanel, M. (1987). "Vibrational study of ionic association in aprotic solvents. 11. Formation and structure of ... When there is about one solvent molecule between cation and anion, the ion pair may be termed solvent-shared. Lastly, when the ... Ion pairs are also classified according to the nature of the interaction as contact, solvent-shared or solvent-separated. The ...
Ideally, the product of the reaction is insoluble in the reaction solvent. Thus, it precipitates as it is formed, preferably ... Precipitation is also useful in purifying products: crude bmim-Cl is taken up in acetonitrile, and dropped into ethyl acetate, ... This is known as the ionic equation. Ag + + NO 3 − + K + + Cl − ⟶ AgCl ↓ + K + + NO 3 − {\displaystyle {\ce {Ag+ + NO3^- + K+ ... The precipitation may occur if concentration of a compound exceeds its solubility (such as when mixing solvents or changing ...
... reference for nonaqueous work as it turns out the platinum is rapidly poisoned by many solvents including acetonitrile[citation ... and unmeasurable junction potentials to the cell in the form of a liquid-liquid junction as well as different ionic composition ... Much as pKa are related between solvents, but not the same, so is the case with E°. While the SHE might seem to be a reasonable ... The ferrocene (II/III) couple should lie around 400 mV versus this Ag/AgCl QRE in an acetonitrile solution. This potential will ...
Reaction of the ionic liquid layer with two molar equivalents of water gives the crystalline product ( H 5 O 2 ) [ H 3 O ⋅ 18 ... The dipole moment of 18-crown-6 varies in different solvent and under different temperature. Under 25 °C, the dipole moment of ... 18-Crown-6 can also be purified by recrystallisation from hot acetonitrile. It initially forms an insoluble solvate. Rigorously ... For example, using 18-crown-6, potassium acetate is a more powerful nucleophile in organic solvents: [K(18-crown-6)+]OAc− + ...
Their surrounding environment (pH, ionic strength, buffer ion, presence of a co-solvent, and temperature) has an influence on ... The mobile phase generally consists of an aqueous portion with an organic addition, such as methanol or acetonitrile. When a ... The polarity index is a measure of the polarity of the solute-solvent interactions. It depends strongly on the organic solvent ... A small amount of organic solvent is often added to the mobile phase to help improve efficiency and to improve separations of ...
The advantage of the anion exchange in favour of a non-coordinating anion is that the resulting ionic liquid has much greater ... Since hexafluorophosphate salts are often insoluble in water but soluble in polar organic solvents, even the addition of ... oxide in acetonitrile: Cu2O + 2 HPF6 + 8 CH3CN → 2 [Cu(CH3CN)4]PF6 + H2O While the hexafluorophosphate ion is generally inert ... Room temperature ionic liquids such as 1-butyl-3-methylimidazolium hexafluorophosphate (typically abbreviated as bmimPF6) have ...
Their advantages for this are: they are very strong bases in many solvents and their conjugate acids are inert and non-HBD ... This article focuses on those phosphazenes with the formula RN=P(NR2)3. Phosphazene bases are strong non-metallic non-ionic and ... Perhaps the best known phosphazene bases are BEMP with an acetonitrile pKa of the conjugate acid of 27.6 and the phosphorimidic ...
A suitable oxidizing agent is iron (III) chloride (FeCl3). Water, methanol, ethanol, acetonitrile and other polar solvents may ... For this purpose, ionic dopants are added to the basic substances of the polymer, forming a conductive surface layer on the ...
In the case of polymer solutions, polymer-polymer, solvent-solvent and polymer-solvent interactions have to be taken into ... Polymers for which UCST relies on non-ionic interactions are very sensitive to ionic contamination. Small amounts of ionic ... polyethylene in diphenylether or polymethylmethacrylate in acetonitrile. An LCST is observed for, e.g., polypropylene in n- ... Three-dimensional covalently linked polymer networks are insoluble in all solvents, they merely swell in good solvents. ...
Acetonitrile is less basic than DMSO, and, so, in general, acids are weaker and bases are stronger in this solvent. Some pKa ... ionic charges are omitted in generic expressions). K. b. =. [. M. p. (. O. H. ). q. −. 1. ]. [. O. H. ]. [. M. p. (. O. H. ). q ... Solvents and Solvent Effects in Organic Chemistry (3rd ed.). Wiley-VCH. ISBN 3-527-30618-8. .. Chapter 4: Solvent Effects on ... pKa values of organic compounds are often obtained using the aprotic solvents dimethyl sulfoxide (DMSO)[34] and acetonitrile ( ...
Owing to its very high acidity and good compatibility with organic solvents it has been employed as a catalyst in a wide range ... Its pKa value in water cannot be accurately determined but in acetonitrile it has been estimated as −0.10 and in 1,2- ... The anion is widely used in ionic liquids (e.g.trioctylmethylammonium bis(trifluoromethylsulfonyl)imide), since it is less ... Wilson, Gregory J.; Hollenkamp, Anthony F.; Pandolfo, Anthony G. (July-August 2007). "Resolving Ambiguous Naming for an Ionic ...
In low-molecular-weight formulations (e.g. PEG 400), it is used in Hewlett-Packard designjet printers as an ink solvent and ... PEG is soluble in water, methanol, ethanol, acetonitrile, benzene, and dichloromethane, and is insoluble in diethyl ether and ... It is coupled to hydrophobic molecules to produce non-ionic surfactants. PEGs potentially contain toxic impurities, such as ... Dimethyl ethers of PEG are the key ingredient of Selexol, a solvent used by coal-burning, integrated gasification combined ...
Olah, George A.; Shih, Joseph G.; Singh, Brij P.; Gupta, B. G. B. (1983). "Ionic fluorination of adamantane, diamantane, and ... It is practically insoluble in water, but readily soluble in nonpolar organic solvents. Adamantane has an unusually high ... Reaction of either compound with acetonitrile affords the acetamide, which is hydrolyzed to give 1-adamantylamine: Adamantane ... This indicates that the reaction occurs via an ionic mechanism. The first fluorinations of adamantane were conducted using 1- ...
Acetonitrile is less basic than DMSO, and, so, in general, acids are weaker and bases are stronger in this solvent. Some pKa ... It has a high dielectric constant (relative permittivity), making it a good solvent for ionic species. ... Solvents and Solvent Effects in Organic Chemistry (3rd ed.). Wiley-VCH. ISBN 3-527-30618-8.. Chapter 4: Solvent Effects on the ... pKa values of organic compounds are often obtained using the aprotic solvents dimethyl sulfoxide (DMSO)[31] and acetonitrile ( ...
In order to exfoliate the nanotubes, they are mixed with an ionic liquid in a mortar and pestle. The diazonium salt is added ... Friedman, Lester; Jurewicz, Anthony T.; Bayless, John H. (March 1969). "Influence of solvent on diazoalkane-alkanediazonium ion ... The reaction of the surface with a solution of diazonium salt in acetonitrile for 2 hours in the dark is a spontaneous process ... Price, B. Katherine (2005). "Green Chemical Functionalization of Single-Walled Carbon Nanotubes in Ionic Liquids". Journal of ...
ˈklɔːraɪd/,[7] commonly known as salt (though sea salt also contains other chemical salts), is an ionic compound with the ... The attraction between the Na+ and Cl− ions in the solid is so strong that only highly polar solvents like water dissolve NaCl ... Acetonitrile. 0.003 Acetone. 0.00042 ... g NaCl / 1 kg of solvent at 25 °C (77 °F))[17]. ... In other words, NaCl has no effect on system pH[20] in diluted solutions where the effects of ionic strength and activity ...
Solutions of KCl are common standards, for example for calibration of the electrical conductivity of (ionic) solutions, since ... KCl is soluble in a variety of polar solvents. Solubility[17] Solvent. Solubility. (g/kg of solvent at 25 °C) ... Acetonitrile. 0.024 Acetone. 0.00091 Formamide. 62 Acetamide. 24.5 Dimethylformamide. 0.17-0.5 ...
It reacts with paper rubber and wood, and ignites many organic solvents. It can be used to nitrate various organic compounds at ... Very weak absorption at 12.19 μm shows a very small quantity of ionic nitrate exists, so this compound is mostly covalent. Dove ... An adduct is also formed with acetonitrile. When mixed with petrol or l-hexene, or other unsaturated hydrocarbons, vanadyl ... Vanadium metal reacts with dinitrogen tetroxide with an acetonitrile catalyst at 0 °C to yield mononitratodioxovanadium(V), ...
... is one of the strongest neutral nitrogenous bases with an extrapolated pKa value of 42.1 in acetonitrile and is ... The compound is very well soluble in non-polar solvents, such as hexane, toluene or tetrahydrofuran, and is usually ... The neutral superbase P4-t-Bu is superior to ionic bases if those are sensitive to oxidation or side reactions (such as ...
In general, such neutralization reactions are represented by one simple net ionic equation: OH−(aq) + H+(aq) → H2O(l). This ... Sodium hydroxide used in this manner replaced many solvent-based systems in the early 1990s[citation needed] when ... It is a white solid ionic compound consisting of sodium cations Na+. and hydroxide anions OH−. . ... Water and sodium hydroxide detergent-based parts washers are considered to be an environmental improvement over the solvent- ...
It is by far the most studied chemical compound and is described as the "universal solvent"[18][19] and the "solvent of life".[ ... The ionic product of pure water,Kw has a value of about 10−14 at 25 °C; see data page for values at other temperatures. Pure ... acetonitrile. Partially miscible with Diethyl ether, Methyl Ethyl Ketone, Dichloromethane, Ethyl Acetate, Bromine. ... An example of an ionic solute is table salt; the sodium chloride, NaCl, separates into Na+. cations and Cl−. anions, each being ...
This indicates that the reaction occurs via an ionic mechanism.[8]. FluorinationEdit. The first fluorinations of adamantane ... It is practically insoluble in water, but readily soluble in nonpolar organic solvents.[21] Adamantane has an unusually high ... Reaction of either compound with acetonitrile affords the acetamide, which is hydrolyzed to give 1-adamantylamine:[46] ... Olah, George A.; Shih, Joseph G.; Singh, Brij P.; Gupta, B. G. B. (1983). "Ionic fluorination of adamantane, diamantane, and ...
This is known as the ionic equation. Ag. +. +. NO. 3. −. +. K. +. +. Cl. −. ⟶. AgCl. ↓. +. K. +. +. NO. 3. −. {\displaystyle {\ ... Precipitation may also occur when an antisolvent (a solvent in which the product is insoluble) is added, drastically reducing ... crude bmim-Cl is taken up in acetonitrile, and dropped into ethyl acetate, where it precipitates.[4] Another important ... Ideally, the product of the reaction is insoluble in the reaction solvent. Thus, it precipitates as it is formed, preferably ...
ionic metal hydride. Beryllium hydride. Left (gas phase): BeH2. covalent metal hydride. Right: (BeH2)n (solid phase). polymeric ... This is because the signal from light-water (1H2O) solvent molecules interfere with observing the signal from the molecule of ... Deuterium oxide is used in nuclear magnetic resonance spectroscopy when using water as solvent if the nuclide of interest is ... Iran produced deuterated solvents in early 2011 for the first time.[64] ...
Sulfonic acids have functionality R−S(=O)2−OH.[20] They are strong acids that are typically soluble in organic solvents. ... It is prepared from the corresponding sulfurane 1 with xenon difluoride / boron trifluoride in acetonitrile to the sulfuranyl ... the ylidic carbon-sulfur bond is highly polarized and is better described as being ionic. Sulfonium ylides are key ...
ionic metal hydride. Beryllium hydride. Left (gas phase): BeH2. covalent metal hydride. Right: (BeH2)n (solid phase). polymeric ... This is because the signal from light-water (1H2O) solvent molecules interfere with observing the signal from the molecule of ... Deuterium oxide is used in nuclear magnetic resonance spectroscopy when using water as solvent if the nuclide of interest is ... Iran produced deuterated solvents in early 2011 for the first time.[68] ...
"Ionic Solids". Retrieved 7 June 2011. Weller, Mark. "Transition Metal Oxides" (PDF). University of Southampton. Retrieved 7 ... A variety of probe molecules can be used including: ammonia, pyridine, acetonitrile, carbon monoxide, and carbon dioxide. Two ... solvent effects, diffusion rate, etc.) calls for greater care to be taken to control these variables to produce consistent ...
The identity of the solvent can have a dramatic effect on the equilibrium shifting it to the right-hand side, greatly ... Fluorides include compounds that contain both ionic fluoride and those where fluoride does not dissociate. The nomenclature ... fluoride source in acetonitrile[18] and its reactivity shows significant potential.[19][20] ... When relatively unsolvated, for example in nonprotic solvents, fluoride anions are called "naked". Naked fluoride is a very ...
In inorganic reactions, water is a common solvent, dissolving many ionic compounds, as well as other polar compounds such as ... "Water, the Universal Solvent". USGS. Archived from the original on 9 July 2017. Retrieved 27 June 2017.. ... Water is vital both as a solvent in which many of the body's solutes dissolve and as an essential part of many metabolic ... Water is widely used in chemical reactions as a solvent or reactant and less commonly as a solute or catalyst. ...
It is convention to ignore the fact that a proton is heavily solvated (bound to solvent). With this simplification in mind, ... the donor-acceptor bond is viewed as simply somewhere along a continuum between idealized covalent bonding and ionic bonding.[5 ... Acetonitrile N 60 Et2O O 78.8 THF O 90.4 acetone O 76.0 ... without having a particular solvent in mind. It seems to me ... The variability of the colors of iodine solutions reflects the variable abilities of the solvent to form adducts with the Lewis ...
He investigated ionic liquids and their application to exfoliation of graphene and black phosphorus. Prezhdo proposed a ... Lett., 91, L19 (2006) C. Brooksby, O. V. Prezhdo, P. J. Reid, "Molecular dynamics study of the weakly solvent dependent ... "Uniform diffusion of acetonitrile inside carbon nanotubes favors supercapacitor performance", Nano Lett., 8, 2126 (2008) V. V. ... Rev., 113, 4496 (2013). V. V. Chaban, O. V. Prezhdo, "Ionic and molecular liquids: hand in hand for robust engineering", J. ...
When both ions are similar in size (Cs+ ionic radius 174 pm for this coordination number, Cl− 181 pm) the CsCl structure is ... solvent). Caesium chloride is a reagent in traditional analytical chemistry used for detecting inorganic ions via the color and ... acetonitrile (0.083 g/L at 18 °C), ethylacetates and other complex ethers, butanone, acetophenone, pyridine and chlorobenzene. ... and the conductivity is not electronic but ionic. The conductivity has a value of the order 10−7 S/cm at 300 °C. It occurs ...
... chloride and a solvent mixture of acetonitrile, water and carbon tetrachloride. RuO4 readily cleaves double bonds to yield ... ISBN 978-0-7514-0413-5. Farmer, V.; Welton, T. (2002). "The oxidation of alcohols in substituted imidazolium ionic liquids ... One of the few solvents in which RuO4 forms stable solutions is CCl4. RuO4 is prepared by oxidation of ruthenium(III) chloride ...
They all have very large atomic and ionic radii and exhibit an unusually large range of physical properties. While actinium and ... The distinctive ability of thorium salts is their high solubility both in water and polar organic solvents. Protactinium ... acetonitrile). Oxidation states +3, +5 and +6 are typical for aqueous solutions, but also in the solid state. Tetravalent ... Actinium is chemically similar to lanthanum, which is explained by their similar ionic radii and electronic structures. Like ...
"Evaluation of Solvent Effects in Isotropic and Anisotropic Dielectrics and in Ionic Solutions with a Unified Integral Equation ... and acetonitrile electrostatic effects are dominant while in carbon tetrachloride, benzene, and chloroform other ... If it were necessary to consider each solvent molecule as a separate molecule, the computational cost of modeling a solvent- ... Modeling the solvent as a polarizable continuum, rather than individual molecules, makes ab initio computation feasible. Two ...
The proteins are eluted by a gradient of increasing amounts of an organic solvent, such as acetonitrile. The proteins elute ... but this interaction is enhanced by applying a protein sample to HIC resin in high ionic strength buffer. The ionic strength of ... Ion exchange chromatography separates compounds according to the nature and degree of their ionic charge. The column to be used ... Consequentially, proteins of a certain range in size will require a variable volume of eluent (solvent) before being collected ...
Solvents have significant effects on the KATRP values. The KATRP value increases dramatically with the polarity of the solvent ... Toluene, 1,4-dioxane, xylene, anisole, DMF, DMSO, water, methanol, acetonitrile, or even the monomer itself (described as a ... proving to be more tolerant of these functionalities than ionic polymerizations. It provides increased control of molecular ... The polymerization must take place in solvent/monomer mixture, which changes to solvent/monomer/polymer mixture gradually. The ...
A comparative electrochemical study of diffusion in room temperature ionic liquid solvents versus acetonitrile ... A comparative electrochemical study of diffusion in room temperature ionic liquid solvents versus acetonitrile CHEMPHYSCHEM, 6 ... ionic liquids, N,N,N ,N -tetramethyl-para-phenylenediamine, CHANNEL FLOW CELL, POTENTIAL STEP CHRONOAMPEROMETRY, ORGANIC- ... SOLVENTS, DISK ELECTRODES, COEFFICIENTS, VOLTAMMETRY, COMPROPORTIONATION, TETRAFLUOROBORATE, MICROELECTRODE, PARAMETERS Related ...
... nitrogen containing solvents including acetonitrile, pyridine, and the like; lower ketones such as acetone and methyl ethyl ... contains about 0.005-10 moles per liter of ionic species and preferably about 0.001-0.5 mole per liter of ionic species. ... The above ionic and electrolyte species are given for illustrative purposes only. A researcher would be able to formulate ... Examples of an electrolyte for a typical electrophoresis system are mixtures of water with organic solvents and salts. ...
Davidson, W.R.; Kebarle, P., Ionic Solvation by Aprotic Solvents. Gas Phase Solvation of the Alkali Ions by Acetonitrile, J. Am ...
Davidson, W.R.; Kebarle, P., Ionic Solvation by Aprotic Solvents. Gas Phase Solvation of the Alkali Ions by Acetonitrile, J. Am ...
"Hollow Fiber Supported Ionic Liquids Liquid-Phase Micro-extraction Followed by High-Performance Liquid Chromatography for the ... as the synergistic extraction solvent) were dissolved by acetonitrile in a mixture ratio of 3:1, and then injected slowly into ... Selection of extraction solvent The selection of an appropriate extraction solvent was very important for the IL-HF-LPME method ... Selection of extraction solvent The selection of an appropriate extraction solvent was very important for the IL-HF-LPME method ...
With the exception of THF (anhydrous ,99%) obtained from Sigma-Aldrich, all solvents were re-distilled from glass prior to use. ... Table 1 Reaction of pyrrole-2-carboxaldehyde (1) with phenyl acetonitrile (2) in the room temperature ionic liquids, [BMIM][PF6 ... The influence of ionic liquids on the Knoevenagel condensation of 1H-pyrrole-2-carbaldehyde with phenyl acetonitriles - ... Scheme 1 Model Knoevenagel condensation of pyrrole 2-carboxaldehyde with phenyl acetonitrile in an ionic liquid.. ...
... acetonitrile) and NMF (N-methylformamide). The secondary solvent system settled on was the DMSO-TBAHFP solvent system. Each tri ... Initially, an ionic liquid, EMIBF4 (1-ethyl-3-methylimidazolium tetrafluoroborate), was used as the solvent. Subsequent ... The sustained catalytic ability of the ionic liquid was explored and the importance of ionic liquid recovery and reuse will be ... this IL catalyst is able to perform esterication reactions with the addition of an organic solvent that solubilizes the ionic ...
... most solvent-based electrolytes suffer from high solvent volatility at elevated temperatures. Solvent evaporation can result in ... acetonitrile or propylene carbonate (Prod. No. 310328). The ionic liquids shown in Figure 1 have attracted significant ... Ionic liquids can be particularly helpful in lithium ion batteries, by replacing flammable solvents and improving battery ... Ionic liquids, also called room temperature ionic liquids, are organic salts that are liquid at, or close to, room temperature ...
Organic solvents like hexane, acetone, methanol, toluene, dichloromethane, ethyl acetate, acetonitrile, and a mixture of them ... Several parameters such as desorption solvent, type and amount of adsorbent, pH, and ionic strength can affect the extraction ... Acetonitrile was selected as the best desorption solvent for 6 PAHs extracted from water samples by using polydopamine-coated ... Nonpolar organic solvents were found to improve the recovery toward PAHs with a higher ring number [144]. In the extraction of ...
In this work, the low-temperature dehydration of fructose to HMF in different deep eutectic solvents (DES) was investigated. We ... In this work, the low-temperature dehydration of fructose to HMF in different deep eutectic solvents (DES) was investigated. We ... in an aqueous acetonitrile biphasic system in the presence of acidic ionic liquids. Appl. Catalysis A General 451, 1-5. doi: ... thus the latter as solvent strongly limits the yield of HMF. Ionic liquids (ILs) as more recent solvents are interesting in ...
a) one or more electrolyte solvents selected from the group consisting of: N-methyl acetamide, acetonitrile, carbonates, ... the organic electrolyte further comprises one or more ionic electrolyte salts, also as known in the art, to increase the ionic ... Examples of useful liquid electrolyte solvents include, but are not limited to, N-methyl acetamide, acetonitrile, carbonates, ... using acetonitrile as the solvent, was prepared by conventional techniques. The slurry was cast by hand coating using a gap ...
... acetonitrile, and dimethyl sulfoxide. Polar solvents are often found to have a high dielectric constant, although other solvent ... Polar solvents can be used to dissolve inorganic or ionic compounds such as salts. The conductivity of a solution depends on ... as solvent ordering increases and solvent-solvent interactions decrease. Stronger interactions among solvent molecules leads to ... Solvents that can donate H-bonds are referred to as protic, while solvents that do not contain a polarized bond to a hydrogen ...
... be nitrated with sodium nitrate and acidic ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate in acetonitrile solvent ... Tajik, H.; Niknam, K.; Parsa, F. (2009). "Using acidic ionic liquid 1-butyl-3-methylimidazolium hydrogen sulfate in selective ...
Additional components of the buffer known to the art can include organic solvents, e.g., acetonitrile; additives which can act ... Buffer 422 can contain pH buffer, other ionic buffers, filtration aids, denaturation agents, organic solvents, pure water, and ... solvents, e.g., organic solvents such as alcohols, ethers, ketones, polar aprotic solvents, and the like; and supercritical ... The liquid in the liquid mixture containing the macromolecule can be any solvent, for example, water, organic solvents such as ...
ionic radii and decreases in acetonitrile solution for the smaller lanthanides. The plutonium(III) complex 6 exhibits, however ...
Disrupt reversed-phase interaction with solvent or solvent mixtures of adequate non-polar character *Methanol, acetonitrile, ... In their ionic form, basic and acidic compounds become more polar, weakening reversedphase interaction, possibly allowing for ... Example elution solvents are 1-2 volumes of methanol or acetonitrile. pH manipulation during elution can often improve recovery ... A pre-conditioning solvent such as dichloromethane (or solvent used for elution) can be used before conditioning to remove any ...
It was found that the ionic liquids performed better upon dilution with a suitable solvent such as acetonitrile, yielding ... ionic liquid suitably diluted , ionic liquid. Among the ionic liquids, best results were obtained for [bmim][BF4]. Cyclic ... ionic liquids (BF4, PF6 and N(CF3SO2)2), and compared with the oxidation obtained using a traditional solvent/electrolyte ... dichloromethane and acetone and the resulting increase in conductivity of the ionic liquid was in the order: acetonitrile , ...
The influence of the weaker solvent, acetonitrile, pH and the nature and ionic strength of the buffer was studied. Linearity ...
... used iso-molded graphite as anode and a novel electrolyte that consist of ionic liquids and acetonitrile (1:50 vol. IL/solvent ... They showed that higher rate of graphene exfoliation in BMPyrr BTA/acetonitrile solution as compared to other ionic liquids ... including ionic liquid [19, 20], high molecular polymer [21], polar solvent [22], surfactant [23] and inorganic solution [24, ... Vanýsek P (1992) Ionic conductivity and diffusion at infinite dilution. CRC Press, Boca Raton, pp 111-113Google Scholar ...
... as an extraction solvent [35], solid-liquid extraction using methanol or acetonitrile as an extraction solvent [36, 37], solid- ... The most common extraction techniques that are widely used in food safety studies are ionic-pair extraction employing methyl ... including minimization of solvent usage, simplification of extract clean-up, and material cost reduction. This method was ...
... acetonitrile, ionic liquids (1-butyl-3-methylimidazolium hexafluorophosphate, [bmim][PF6], and 1-butyl-3-methylimidazolium tris ... The use of such alternative solvents led to efficient and selective protocols for the oxidation of cyclohexane. Moreover, ... tuning the alcohol/ketone selectivity was possible by choosing the suitable solvent. ... Keywords: ionic liquid; supercritical carbon dioxide; cyclohexane; oxidation; C-scorpionate; catalyst ionic liquid; ...
Ionic Liquid)s Used as Green Solvent and Ultrasound Responded Materials: 10.4018/978-1-5225-1971-3.ch015: Ionic liquids (ILs) ... have been known as a class of green solvent and played an important role in green chemistry in recently years. Materials based ... alcohol and acetonitrile (Bester-Rogac, Stoppa, Hunger, Hefter, & Buchner, 2011; Zheng, Wang, Luo, Zhou, & Yu, 2013) . ... "Ionic Liquids and Poly (Ionic Liquid)s Used as Green Solvent and Ultrasound Responded Materials." In Applied Environmental ...
These nonaqueous solvents are typically used as multicomponent mixtures, into which a salt is dissolved to provide ionic ... acetonitrile, propiononitrile, ethyl acetate, methyl propionate, ethyl propionate and the like. ... a polar solvent such as alcohols or aprotic organic solvents. Numerous organic solvents have been proposed as the components of ... For high-power devices, the ionic sources and sinks are connected to the separator by an element with large ionic conductivity ...
... neat or mixed with other ionic liquids, molecular solvents and/or salts), molten salts and inorganic acids. ... Their 1999 paper reports K=6 S/m and μ=1 cP for mixtures of EMIm-PF6 with acetonitrile. No data are included for EMIm-BF4, ... Also mixtures of these solvents with ionic liquids. Other suitable liquids are inorganic acids, molten salts, ionic liquids, ... of ionic liquids with moderately polar solvents makes it possible to design mixtures of molecular solvents with ionic liquids ...
Solvents: water, 0-100% alchohols, acetonitrile, other common organic solvents. Cleaning & Regenerating Simple: 1-5 column ... So from my Poros HS operating instructions: Chemical Resistance pH 1-14 (up to 0.5M NaOH, 1M HCl) Ionic strength: 0-5M all ... isopropanol or acetonitrile with the acid or base It recommends that you inject viscous or aggressive solvents directly, making ... resuspend in packing solvent and repack the column. Ive done this for several of my columns and it works OK. Check if you have ...
estimated from the solvents conductivity. The ratio of the respective ionic strengths is n. s. /. n. b. =. (. κ. b. -. 1. /. κ ... "Hydrogen Halides in Acetonitrile. III. Electrical Conductance." J. Am. Chem. Soc. 81, 3854-3858 (1959). ... Assuming that ionic currents are carried by dissociated HBr, we can estimate Λ. 0. from the previously measured value Λ. b. =. ... "Ionic Association. III. The Equilibrium between Ion Pairs and Free Ions." J. Am. Chem. Soc. 80, 5059-5061 (1958). ...
... acetonitrile, propylene carbonate, etc.) some recent efforts have also been devoted to employing low viscosity ionic liquids in ... Solvents with ether functionality have since taken precedence given that they are more stable during charging and also less ... pure ionic or mixed ionic/electronic), can be used for selective transport of oxygen or hydrogen in the form of ionic flux ... These materials are known to have high ionic conductivity with ionic transport number for Na+ or K+ close to unity (Badwal, ...
Some organic solvents such as DMF are very viscous and do not wet the surface of the fluorocarbon filter very well. A good tip ... 80:20 0.10M NaNO3/Acetonitrile. Note that in many cases where sodium nitrate is shown, many workers have used acetate, sulfate ... We recommend sodium nitrate, which has shown to minimize ionic interferences very consistently for neutral and anionic ... With the organic solvents, a fluorocarbon filter is generally used. The filter pore membrane size is generally 0.45m (micron). ...
... ion in methanol and acetonitrile solutions. Ionic liquids (ILs) constitute a group of molten organic electrolytes whose ... The temperature elevation causes an increase in their limiting molar conductances in the three solvents under investigation. ... whereas these exhibit slight ionic association in acetonitrile within the investigated temperature range. ... Their electrical conductances have been measured as a function of their concentrations in water, methanol, and acetonitrile at ...
  • The Knoevenagel condensation of a series of substituted phenyl acetonitriles with 1 H -pyrrole-2-carbaldehyde was examined in seven 1-butyl-3-methylimidazolium based ionic liquids and three protic ionic liquids. (
  • Specifically we have developed a considerable interest in emerging flow chemistry technologies and the possible application of room temperature ionic liquids to enhancing the outcome of simple synthetic procedures. (
  • 9,24 While the reactions proceeded with moderate efficiency and yield, we believed that ease of anion modification with room temperature ionic liquids would allow us to select the most appropriate system for rapid access to this compound series and potentially simplify reaction work up by product precipitation. (
  • 24-27 We also viewed the Knoevenagel condensation as an ideal opportunity to probe the effects of different ionic liquids on the reaction outcome. (
  • Our efforts commenced with the examination of one of the archetypal room temperature ionic liquids, [BMIM][PF 6 ] on the Knoevenagel condensation of pyrrole-2-carboxaldehyde ( 1 ) with phenyl acetonitrile ( 2 ). (
  • Hollow Fiber Supported Ionic Liquids Liquid-Phase Micro-extraction Followed by High-Performance. (
  • Wang, Meng;Cheng, Chunsheng;Liu, Chunbo;Yang, Yaling 2018-01-01 00:00:00 Abstract A rapid, simple, reliable and efficient hollow fiber supported ionic liquids liquid-phase micro-extraction method (IL-HF-LPME) followed by high-performance liquid chromatography was successfully applied to the determination of four kinds of polycyclic aromatic hydrocarbons (PAHs) in milk samples. (
  • Ionic liquids, also called room temperature ionic liquids, are organic salts that are liquid at, or close to, room temperature. (
  • this combination of properties makes ionic liquids useful as "green" solvents for energy applications and industrial processes. (
  • Another useful aspect of some ionic liquids is their broad window of electrochemical stability, which can be as large as 6.0 V. 1 This window makes these ionic liquids promising candidates for use as electrolytes for electrochemistry. (
  • The ionic liquids shown in Figure 1 have attracted significant attention as alternative electrolytes for EAP-systems. (
  • The electrochemical oxidation of the substituted phenol 2,6-di- t -butylphenol is studied at platinum electrodes using a number of 1-butyl-3-methylimidazolium (bmim) ionic liquids (BF 4 , PF 6 and N(CF 3 SO 2 ) 2 ), and compared with the oxidation obtained using a traditional solvent/electrolyte system (CH 3 OH/CH 2 Cl 2 and LiClO 4 ). (
  • It was found that the ionic liquids performed better upon dilution with a suitable solvent such as acetonitrile, yielding higher conductivities due to ion separation. (
  • Among the ionic liquids, best results were obtained for [bmim][BF 4 ]. (
  • Pagni RM (2003) In: Rogers RD et al (eds) Green industrial applications of ionic liquids. (
  • Matsumoto H (2005) In: Ohno H (ed) electrochemical aspects of ionic liquids. (
  • Wilkes J (2003) In: Rogers RD et al (eds) Green industrial applications of ionic liquids. (
  • 6. A method as in claim 1 in which said liquid is selected from the group consisting of ionic liquids and molten salts. (
  • Ionic Liquids and Poly (Ionic Liquid)s Used as Green Solvent and Ultrasound Responded Materials. (
  • Ionic liquids (ILs) have been known as a class of green solvent and played an important role in green chemistry in recently years. (
  • Since some ILs are liquid in room temperature, they are also called room temperature ionic liquids (RTILs). (
  • As a well-known green solvent, ionic liquids (ILs) are actively studied in recent decades. (
  • Ionic liquids (ILs) constitute a group of molten organic electrolytes whose chemical and physical properties could be conveniently engineered by judicious choice of their anions, cations, and the substituents. (
  • The activity of three different lipases, a glycosidase and a protease in ionic liquids has been studied. (
  • Ambient temperature ionic liquids are a new class of solvents that are nonvolatile and nonflammable and thus an interesting alternative to classical organic solvents. (
  • A validated ion chromatographic method was developed and applied for the determination of the maximum solubility of pyridinium ionic liquids in several aromatic solvents. (
  • Mixtures of pyridinium ionic liquids and aromatic solvents were diluted with acetonitrile and acetone on a 1:1:2 weight base before the analysis. (
  • The standard curves for both pyridinium ionic liquids ([4-mebupy]BF 4 and [3-mebupy]N(CN) 2 ) were linear (r 2 = 0.9980-0.9998) in all aromatic solvents (toluene, benzene, ethylbenzene and o-xylene) in the concentration range of 5.37-241 mg kg -1 . (
  • The limit of detection for both pyridinium ionic liquids in all solvents varied between 0.73 and 2.6 mg kg -1 . (
  • This assay has been successfully applied in the determination of the maximum solubilities of both pyridinium ionic liquids in several aromatic solvents. (
  • Ionic liquids (ILs) have been acclaimed as green reaction media and catalysts as they are non-volatile, highly solvating, excellent ionic conductivity, good electrochemical properties, etc [25 - 30] , 29 ). (
  • Room temperature ionic liquids (RTILs) have been given careful consideration by academia and industries because of their environment-friendly properties, particularly their abilities in green chemistry. (
  • Specifically, in 1982 John Wilkes presented tetrachloroaluminate ionic liquids based on 1-alkyl-3-methyl-imidazolium as cation, Figure (2) 3. (
  • This can be named as the second generation of ionic liquids, (which is yet a standout amongst the most broadly utilized cations today), Figures (3, 4) 4, 5. (
  • The third generation, which sometimes featured in literature under the term "designer solvents" or "task-specific ionic liquids", was presented by Jim Davis and others in 1998 6 figure (5). (
  • On April 2000, Advanced Workshop on Green Industrial uses of Ionic Liquids was held in Heraklion, Crete, Greece. (
  • This was the first international meeting devoted to research in ionic liquids (salts with melting points below 100 oC) 7. (
  • It was proposed to explore the promise of ionic liquids as well as to set a research agenda for the field. (
  • The significance of ionic liquids is elucidated by many scientific programmes and labs. (
  • Tpoics in ionic liquids 11). (
  • Ionic Liquids are characterized as salts with a melting point below the boiling point of water and They are completely ionic. (
  • Since ionic liquids have very low vapor pressure and do not substantially vaporize at room temperature, they are not liable to volatilization or cause ignition, unlike typical organic solvents. (
  • However, ionic liquids suffer from a shortcoming in that the electrical resistance thereof is higher than that of an electrolyte solution obtained through dissolution into an organic solvent, such as acetonitrile. (
  • Another embodiment contains up to about but not more than 10 mol percent of a molecular solvent such as acetone. (
  • Solubility of NaCl in various solvents (g NaCl / 1 kg of solvent at 25 °C)[3] H2O 360 Formamide 94 Glycerin 83 Propylene glycol 71 Formic acid 52 Liquid ammonia 30.2 Methanol 14 Ethanol 0.65 Dimethylformamide 0.4 1-Propanol 0.124 Sulfolane 0.05 1-Butanol 0.05 2-Propanol 0.03 1-Pentanol 0.018 Acetonitrile 0.003 Acetone 0.00042 P.1 and more soluble in water than methanol. (
  • Acrylonitrile is soluble in water and most common organic solvents such as acetone, benzene, carbon tetrachloride, ethyl acetate, and toluene. (
  • Two common extraction solvent systems, namely acidified aqueous methanol and acidified aqueous acetone, were used to extract blackberry phenolics, and the antioxidant properties of the recovered extracts were compared. (
  • The acrylonitrile is a colorless to pale yellow liquid and volatile liquid that is soluble in water and most common organic solvents such as acetone, benzene, carbon tetrachloride, ethyl acetate, and toluene. (
  • Elution Disrupt hydrophobic interactions between the analyte and sorbent functional groups with an organic solvent or solvent combination of sufficient non-polar character. (
  • In order to quantitate selectivity differences, we employed a previously described method 1 that compares the square of the correlation coefficient (R 2 ) to calculate the selectivity difference (S-value) between two sets of conditions (i.e., two columns, high and low pH mobile phase, organic solvent, etc. (
  • In addition, compromises are needed to ensure the technique is fast, easy, and cheap as well as reducing organic solvent consumption. (
  • Developments in classical SLE, where shaking by hand usually ensures the partitioning of the analytes between the solid matrix and the organic solvent, include sonication, which is generally preferred to aid this contact between the two phases and promote the extraction efficiency. (
  • Polar or even non-polar silica stationary phases have been used in conjunction with highly organic solvent. (
  • an organic solvent used as an antiinflammatory agent. (
  • dīmeth´əl sulfok´sīd), n an antiinflammatory agent and organic solvent. (
  • It has been found that the photovoltaic performance of ISIL-based electrolytes can even rival that of organic solvent-based electrolytes. (
  • performing a second charge after the completion of the rest period to a voltage from about 4.275V to about 4.39V, wherein the electrolyte comprises LiPF 6 and/or LiBF 4 at a total concentration from about 0.9M to about 2.5M and a solvent comprising ethylene carbonate and an organic solvent comprising dimethyl carbonate, methyl ethyl carbonate, γ-butyrolactone, γ-valerolactone or a combination thereof. (
  • As the electrolyte, an electrolyte solution is typically used in which an oxidation-reduction pair, such as I − /I 3 − , is dissolved in an organic solvent, such as acetonitrile. (
  • 6 Ions are introduced using electrolyte solutions such as tetraalkylammonium salts dissolved in water, acetonitrile or propylene carbonate (Prod. (
  • Best results were obtained for the conventional solvent and electrolyte, where the oxidation was found to take place via an indirect method. (
  • 5. A method as in claim 1 in which said liquid comprises a solution of an electrolyte in a solvent, and wherein said solvent is selected from the group consisting of amides, alcohols, glycols, esters, ketones, organic carbonates, organic phosphates, and mixtures of one or more of the foregoing. (
  • Synergistic effects were observed when GSCN and MBI were used together in the ionic liquid-based electrolyte. (
  • In this case, optimal open-circuit voltage and total conversion efficiency were obtained among the ionic liquid electrolytes studied mainly due to the more efficient retardation of the recombination loss reaction at the TiO2/electrolyte interface. (
  • Certain of the latter embodiments may also contain molecular additives from the group of acetonitrile (CH{sub 3}CN), succinnonitrile (CH{sub 2}CN){sub 2}, and tetraglyme (CH{sub 3}--O--CH{sub 2}--CH{sub 2}--O--){sub 2} (or like solvents) solvated to a Mg{sup +2} cation to lower the freezing point of the electrolyte below room temperature. (
  • A liquid, predominantly lithium-conducting, ionic electrolyte is described which has exceptionally high conductivity at temperatures of 100 C or lower, including room temperature. (
  • Further, a liquid ionic electrolyte which has been rubberized by addition of an extra proportion of anionic polymer, and which has good chemical and electrochemical stability, is described. (
  • Electrochemical testing of the ether-functionalised sulfonium IL was conducted using activated carbon composite electrodes to inspect the performance of the IL as a solvent-free electrolyte for EDLC application. (
  • These salts were studied using a conventional electrolyte (TBAP in acetonitrile) and alternative electrolyte based DES (LiTfO:6EG) for 3- and 2- electrodes configuration devices. (
  • An ionic liquid tetraethylammonium bis(trifluoromethylsulfonyl)imide (TEATFSI) is synthesized as the supporting electrolyte in an all-organic redox flow battery system with acetonitrile as the solvent. (
  • An electrolyte composition containing an ionic liquid and conductive particles, an electrolyte composition containing an ionic liquid and oxide semiconductor particles and optionally containing conductive particles, and an electrolyte composition containing an ionic liquid and insulating particles are provided. (
  • Other well-known electrolytes include one using a nonvolatile ionic liquid, one in which the liquid electrolyte is made into a gel using an appropriate gelling agent to be quasi-solidified, and one using a solid semiconductor, such as a p-type semiconductor. (
  • Although the apparent transport properties are improved relative to the alkyl-functionalised analogue, the ether-functionalised sulfonium cation-based IL exhibits moderately high viscosity, and poorer conductivity, when compared to traditional EDLC electrolytes based on organic solvents (propylene carbonate and acetonitrile). (
  • 1,444 K) Solubility in water 1510 g/L (0 °C) 1670 g/L (25 °C) 4330 g/L (100 °C) Solubility soluble in ethanol, propanol, ethanediol, ammonia Solubility in methanol 3430 g/L (20 °C) Which solvent will dissolve more of the given solute? (
  • Organic reactions in aqueous media or aqueous ethanol media have attracted much attention because both water and ethanol are considerably safe, non-toxic, environmentally-friendly, and cheap compared to organic solvents [18]. (
  • The objective of this study is to characterize the phenolic content and critically examine the antimicrobial activity of leaf extracts H. patens, obtained by maceration, Soxhlet and percolation, using ethanol as 70% solvent. (
  • TLC enables you to evaluate d ifferent solvents and solvent mixtures to find those providing the best separation of your target molecule from the reaction by-products. (
  • xref 166 16 It is soluble in water and many other common organic solvents. (
  • Both ionized and uncharged molecules interact strongly with solvent, and the strength and nature of this interaction influence many properties of the solute, including solubility, reactivity, and color, as well as influencing the properties of the solvent such as the viscosity and density. (
  • Solubility of solid compounds depends on a competition between lattice energy and solvation, including entropy effects related to changes in the solvent structure. (
  • co-solvents" to provide solubility for organics while maintaining many of the properties of pure water. (
  • This is observed in the data of Vorobeva and Karapetyants (Ref. This unusual effect of the temperature on the solubility, although unforeseen for a given system, may be explained both by Debye-Hu¨ckel and ion association Bjerrum theories16 because at such low ionic concentrations the electrostatic interactions are more pronounced and 1971 Apr;60(4):565-7. (
  • The solubility of l-tartaric acid in those selected solvents increases with increasing temperature. (
  • However, as the solvent primarily consists of acetonitrile, there can be issues regarding the solubility of certain analytes. (
  • Basically, this means to know your mixture's solvent compatibility/solubility and the target molecule's possible reactivity toward silica or other media. (
  • Polar solvents have molecular dipoles, meaning that part of the solvent molecule has more electron density than another part of the molecule. (
  • Polar solvents are often found to have a high dielectric constant, although other solvent scales are also used to classify solvent polarity. (
  • Polar solvents can be used to dissolve inorganic or ionic compounds such as salts. (
  • In contrast to its time-resolved behavior in conventional polar solvents, C-102 exhibits wavelength-dependent fluorescence decay behavior in [BMIM][BF4] because of slow solvation dynamics in this viscous medium. (
  • Chloroform), and operates proficiently for separating analytes quickly soluble in non-polar solvents. (
  • Like dissolves like" is a good rule of thumb, i.e., polar solvents dissolve polar compounds. (
  • Use of much more polar solvents within the cell period will lower the retention time in the analytes, whereas a lot more hydrophobic solvents have a tendency to increase retention moments. (
  • Usage of much more polar solvents from the cellular period will reduce the retention time of your analytes, Whilst far more hydrophobic solvents tend to raise retention situations. (
  • So from my Poros HS operating instructions: Chemical Resistance pH 1-14 (up to 0.5M NaOH, 1M HCl) Ionic strength: 0-5M all common salts Buffer additives: all common agents including 8M urea, 6M guanidine/HCl, ethylene glycol, and detergents. (
  • By this measure, water (which dissolves ionic or charged compounds such as inorganic salts) is a most polar solvent, having a dielectric constant of 78 at 25ºC. (
  • Variety of esters has been prepared from versatile carboxylic acids and alcohols under ionic liquid conditions with excellent yields. (
  • The problems connected with these solid polymer electrolytes relate generally to the fact that they usually demonstrate an ionic conductivity which is satisfactory only at higher than ambient temperature, and that the electrolytic membranes have poor mechanical strength and poor dimensional stability. (
  • Samanta, Anunay 2005-09-01 00:00:00 The steady-state and time-resolved fluorescence behavior of Coumarin 102 (C-102) has been investigated in a ionic liquid at room temperature, 1-buty1-3-methylimidazolium tetrafluoroborate, abbreviated here as [BMIM][BF4]. (
  • In this paper, we report the use of ionic liquid 1-butyl-3-methyl-imidazolium chloride [BMIM]Cl on the extraction and isolation of β-glucan from baker's yeast Saccharomyces cerevisiae. (
  • The ionic solution 1-butyl-3-methyl-imidazolium chloride [BMIM]Cl was prepared according to the method of Dupont et al. (
  • Many charts compare parameters and formulations, solvent-solute vs ionic, aqueous vs non-aqueous, toxicology, adoption trends and more. (
  • Triflic acid, H[OTf], a well-known superacid in aqueous media, has been shown to be a weak acid with a pKa of 2.0 in this ionic liquid. (
  • Using aqueous electrodes introduces undefined, variable, and unmeasurable junction potentials to the cell in the form of a liquid-liquid junction as well as different ionic composition between the reference compartment and the rest of the cell. (
  • [3] The best argument against using aqueous reference electrodes with nonaqueous systems, as mentioned earlier, is that potentials measured in different solvents are not directly comparable. (
  • Most importantly, Eurokat phases show extraordinary column lifetime stability and are not affected by aqueous solvents. (
  • Such aqueous eluents produce no harmful waste as with organic solvents such as acetonitrile which necessitate expensive disposal. (
  • More solvent in the aqueous mixture would enhance the dispersive interactions in the mobile phase and would compete with the dispersive interactions between the solute and the alkane chains of the stationary phase. (
  • In their ionic form, basic and acidic compounds become more polar, weakening reversedphase interaction, possibly allowing for weaker elution solvents and/or reduced elution volumes. (
  • Some chemical compounds experience solvatochromism, which is a change in color due to solvent polarity. (
  • As a result, these columns give superior peak shape for basic compounds due to improved loading capacity under low-ionic strength conditions, as well as rapid re-equilibration after changing mobile phase pH. (
  • Traditional solid-liquid extraction (SLE) techniques are thought to be timeâ consuming, lack efficiency in extracting target compounds, and require large volumes of solvents. (
  • This article uses equations for partition coefficients of compounds from water and the gas phase to various solvents to obtain descriptors for pentane-2,4-dione and 21 of its derivatives. (
  • As a solvent for the reaction of a water-insol-uble compound with water, THF is typically an excellent choice because it dissolves both compounds. (
  • Elements & Compounds) a colourless soluble flammable liquid used mainly as a solvent for resins, as a paint remover, and in lacquers, cements, and adhesives. (
  • by comparing the basicity data of related compounds in different solvents, as well as by using isodesmic reactions. (
  • Let's suppose that you are interested in a selected compound, X. , though other compounds far more strongly interested in the solvent moved more rapidly. (
  • This method may be referred to as follows: the compounds contained inside the sample distribute, or partition otherwise in between the shifting solvent, called the mobile stage, as well as particles, called the stationary section. (
  • A wide range of solvents has been used in these reactions including carbon tetrachloride, hexane, dichloromethane, methanol and acetonitrile. (
  • Solvent polarity is the most important factor in determining how well it solvates a particular solute. (
  • The properties of MeTHF place it between tetrahydrofuran (THF) and diethyl ether in solvent polarity and Lewis base strength. (
  • This enables future measurements of acid strengths (especially of very strong acids) and acidity adjustments in low polarity solvents. (
  • A parameter known as the dielectric constant is a rough measure of solvent polarity or its ability to stabilize charges. (
  • dimethyl sulfoxide , an industrial solvent that has the ability to penetrate plant and animal tissues and to preserve living cells during freezing. (
  • Solvation (or dissolution) describes the interaction of solvent with dissolved molecules. (
  • Solvation is the process of reorganizing solvent and solute molecules into solvation complexes. (
  • In the solvated state, an ion in a solution is surrounded or complexed by solvent molecules. (
  • Polar solvent molecules can solvate polar solutes and ions because they can orient the appropriate partially charged portion of the molecule towards the solute through electrostatic attraction. (
  • The solvent molecules in the immediate vicinity of a solute particle often have a much different ordering than the rest of the solvent, and this area of differently ordered solvent molecules is called the cybotactic region. (
  • Hydrogen bonding among solvent and solute molecules depends on the ability of each to accept H-bonds, donate H-bonds, or both. (
  • Solvent molecules involving oxygen are an exception. (
  • The empirical formula will include all atoms in the title formula including those in solvent molecules that are clearly identified in the structure determination. (
  • In such a case, there will be a robust attraction among the polar solvent and polar molecules within the combination remaining passed with the column. (
  • Polar molecules during the combination will for that reason commit most of their time transferring With all the solvent. (
  • The present invention resides in the field of high-pressure, or high-performance, liquid chromatography (HPLC) assays, particularly for the delivery of reagents, diluents, solvents, and other fluids an HPLC instrument and apparatus system. (
  • This is twice the viscosity of acetonitrile used in hydrophilic interaction chromatography, where it is around 0.4 centipoise. (
  • Solvents of non-polar character (including methanol and isopropanol) disrupt interaction between the compound and sorbent functional groups. (
  • These biocatalysts were evaluated in the kinetic resolution of rac-1-methyl-2-(2,6-dimethylphenoxy)ethyl acetate in different co-solvents (acetonitrile, isopropanol, ethyl ether and tetrahydrofuran). (
  • Four different ionic species are available. (
  • In this study, the thermodynamics, kinetics and mechanisms of the proton reduction (hydrogen evolution) reaction at a platinum electrode have been investigated in the room temperature ionic liquid 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide, using a range of oxyacids (phenols, carboxylic acids, or sulfonic acids) as the proton source. (
  • An ionic liquid is also called a room temperature molten salt, exists as a stable liquid in a broad temperature region, including in the vicinity of room temperature, and is a salt made from a cation and an anion. (
  • Acetonitrile and water (90:10) as mobile phase was used to determine the content of oleanic acid with a gradient elution and flow rate at 1.00 mL · min(-1), detection wavelength at 210 nm, chromatographic column temperature at room temperature. (
  • Paeoniflorin content was determined using acetonitrile and water (18:82) as mobile phase with a gradient elution and flow rate at 1.00 mL · min(-1), detection wavelength at 250 nm, the chromatographic column temperature at room temperature. (
  • OTf] − = [O 3 SCF 3 ] − ) depends on their metal cation ionic radii and decreases in acetonitrile solution for the smaller lanthanides. (
  • Herein, a pathway is presented for the multifold increase of the practical discharge power of these batteries by tailoring the tripartite interactions between the salt cation and anion and the solvent. (
  • A novel cyclic sulfonium cation-based ionic liquid (IL) with an ether-group appendage and the bis{(trifluoromethyl)sulfonyl}imide anion was synthesised and developed for electrochemical double layer capacitor (EDLC) testing. (
  • Reversed-phase sorbents are often conditioned with 1-2 tube volumes of a water miscible solvent such as methanol or acetonitrile. (
  • Example elution solvents are 1-2 volumes of methanol or acetonitrile. (
  • elute solutes more rapidly, the quantity of methanol or acetonitrile in the mobile phase would need to be increased relative to that of water. (
  • Which solvent will dissolve more of the given solute? (
  • The Helium has to have reduced amounts of Hydrocarbons as these can dissolve within the solvent and create baseline sounds. (
  • Solvents are substances used to dissolve, extract, or suspend other substances to form a solution. (
  • In this work, the low-temperature dehydration of fructose to HMF in different deep eutectic solvents (DES) was investigated. (
  • 2 A perusal of some ionic liquid electrolytes (ILEs) shown in Table 1 quickly reveals the trade-offs. (
  • 10 When used without additional solvents, ionic liquid electrolytes significantly improve switching stability of EAP-based devices relative to solution based electrolytes. (
  • The effects of additives guanidinium thiocyanate (GSCN) and N-methylbenzimidazole (MBI) on the photovoltaic performance of dye-sensitized solar cells based on low-viscous, binary ionic liquid and organic liquid electrolytes were investigated. (
  • Expectedly, the least polar (or the most nonpolar) solvents are the alkanes pentane, hexane, heptane (dielectric constant less than two), and the aromatics benzene, toluene, and xylene (dielectric constants less than three). (
  • Moreover, tuning the alcohol/ketone selectivity was possible by choosing the suitable solvent. (
  • Acetonitrile and ethyl acetate (Merck) were distilled over phosphorus pentoxide (P 2 O 5 ) and stored over molecular sieve 4A before use. (
  • The remaining light-yellow oil was re-dissolved in dry acetonitrile (250 mL), and the solution was dropwise added into a well-stirred solution of dry ethyl acetate (1000 mL). (
  • Which of these forces are at play depends on the molecular structure and properties of the solvent and solute. (
  • 2O) can be minimized by adding molecular sieves to the solvent, agitating the mixtureand allowing it to stand for a few hours. (
  • Also the nonpolar aprotic solvent of molecular formula C 4 H 8 O containing this ring. (
  • The heat-sensitive ionomer and modified carbonaceous particles can be formulated in water or water-miscible solvents without agglomeration. (
  • Although the usual choice for the mobile phase is acetonitrile, any aprotic solvent that is miscible with water can be used for this purpose. (
  • In cases where alcohol is used, the concentration should be higher such that they can have a similar degree of retention as a combination of aprotic solvent and water. (
  • The selectivity of the column is adjustable by varying the ionic strength, pH, or organic content of the mobile phase so a mixture (1,2,3) that elutes in the order 1,2,3 under one set of conditions can elute in the order 3,2,1 in other conditions, if so required. (
  • Among the challenges for chemists including discovery and development of inexpensive, non-hazardous and simple environmentally safe chemical processes for selective synthesis by identifying alternative reaction conditions and solvents that much improved selectivity, energy conservation and even less hazardous waste generation are not desirable and inherently safer chemical products. (
  • Nonpolar solvents cannot solvate ions, and ions will be found as ion pairs. (
  • Solvents are generally classified as polar and nonpolar. (
  • Click on one of the buttons below to explore other commonly referenced solvent properties, including lists of substances with which it is miscible or immiscible and bond dipole moment. (
  • It is highly soluble in water and miscible with most organic solvents. (
  • An array of bottles (also referred to as "reagent boxes" or "container assemblies") each contain an enclosed bag or pouch, within which solutions of solvents, reagents, buffers, diluents, and/or other fluid mediums are contained. (
  • All reagents and solvents were used without further purification. (
  • The non-ionic surfactant Triton X-114 (polyethylene glycol tert -octylphenyl ether) was chosen as the extract solvent. (
  • Generally speaking, off-line coupling involved portion assortment, evaporation of solvent, and transfer of analytes on the MS employing probes. (
  • This trend is in line with the dielectric constant and the dipole moment of the solvent used. (
  • Finally, the pKa values of 10 weak oxyacids, covering 16 orders of magnitude in acid strength (2.0 ≥ pKa ≥ 17.8), have been calculated using a voltammetric method and compared with data from conventional solvents (acetonitrile and water) in order to gain insights into how the nature of the solvent (i.e., dielectric properties, Lewis acidity/basicity, hydrogen donating/accepting ability, etc.) influences equilibrium acidity. (
  • The higher the dielectric constant, the more polar the solvent (or any substance for that matter). (
  • In general, solvents with dielectric constants greater than 15 are considered polar. (
  • A series of silica supported functionalized ionic liquid catalysts have been prepared and tested in the hydroxylation of aromatics to phenols with H 2 O 2 under solvent-free conditions. (
  • HILIC uses a polar stationary phase, such as silica or polar bonded phase, and the mobile phase consists of 5- 40% water that is combined with a less polar solvent, such as acetonitrile. (
  • On the other hand, if strong polar interactions are selected to control retention ( e.g . silica gel is chosen as the stationary phase) then a strong dispersive solvent mixture might be selected for the mobile phase ( e.g . an alkane or an alkane/methylene dichloride mixture). (
  • In the process of solvation, ions are surrounded by a concentric shell of solvent. (
  • Water is an excellent solvent for many ions, because it is a highly polar substance. (
  • wherein X represents an aromatic group or an alkyl group, NIon represents a non-ionic, non-ionizable group, R.sub.terminal represents hydrogen, an aromatic group, an alkoxy group, or an alkyl group, and p is an integer from 1 to about 500. (
  • ILs have hardly detectable vapor press as compared with the common used solvent, such as THF, DMF and chloroform and have been treated as a green solvent/medium. (
  • If exchange still causes a problem, it is recommended to use a less hygroscopic solvent, such as chloroform, methylene chloride or acetonitrile. (
  • More specifically, the present invention is directed to a fluid handling system for the delivery of solvent fluids with positive pressure to an HPLC instrument. (
  • HPLC instruments and techniques have become increasingly sophisticated and complex, allowing for the analysis of multiple portions of a sample, utilizing a variety of different solvent fluids or analyzing a variety of samples with the same or different solvents. (
  • HPLC systems known in the field often require that the solvent fluids to be used by the instruments be elevated, so as to take advantage of gravity, drawing down the solvent fluids into the instrument, and thus priming the fluid lines of the HPLC instrument. (
  • In view of the above, there remains a need to provide solvents to HPLC instrumentation without the disadvantages noted above and known in the field. (
  • Embodiments of the present disclosure are directed to a pressurized system for the delivery of fluid mediums, such as solvent fluids, into an HPLC instrument, and to modules within an HPLC instrument such as a pump set, a separation module, or a dilution module. (
  • The fluid connectors lead into the HPLC instrument and thus the present disclosure provides solvent fluids to an HPLC instrument and system at a positive pressure, relative to ambient conditions. (
  • In the case of reverse-phase HPLC, the viscosity of acetonitrile is 0.9-0.86 centipoise (cP). (
  • In the IL-HF-LPME method, a mixture of [OMIM]PF6 and lauric acid, in a ratio of 3:1, was immobilized in the pores of a polypropylene hollow fiber used as extraction solvent. (
  • Most of these methods suffer from various disadvantages such as long reaction periods, harsh experimental procedure and surfactants or ionic liquid that are expensive. (
  • Similarly the central atom of a separate ion or solvent molecule is listed first, e.g. (
  • Apocynin can be nitrated with sodium nitrate and acidic ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate in acetonitrile solvent. (
  • Equilibration introduces a solution similar to the sample load in terms of solvent strength and pH in order to maximize retention. (
  • The influence of the weaker solvent, acetonitrile, pH and the nature and ionic strength of the buffer was studied. (
  • Eh = -200 mV, ionic strength I = 1 x [10.sup. (