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Biuret
Biuret ( ) is a chemical compound with the chemical formula . It is a white solid that is soluble in hot water. A variety of organic derivatives are known. The term "biuret" also describes a family of organic compounds with the chemical formula , where are hydrogen, organyl or other groups. Also known as carbamylurea, it results from the condensation of two equivalents of urea. It is a common undesirable impurity in urea-based fertilizers, as biuret is toxic to plants. Preparation and structure The parent compound can be prepared by heating urea at 150 °C for ~6 hours until it gets slightly cloudy, then recrystallizing from water. After that, it can be recrystallized repeatedly from 2% sodium hydroxide solution and water to finally get base-free crystalline needles of the monohydrate which are free of cyanuric acid. While heating, a lot of ammonia is expelled: : Under related conditions, pyrolysis of urea affords triuret . In general, organic biurets (those with alkyl or aryl gr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biuret Test
In chemistry, the biuret test (IPA: , ), also known as Piotrowski's test, is a chemical test used for detecting the presence of at least two peptide bonds in a molecule. In the presence of peptides, a copper(II) ion forms mauve-colored coordination complexes in an alkaline solution. The reaction was first observed in 1833. In Poland, the biuret test is also known as Piotrowski's test in honor of the Polish physiologist who independently rediscovered it in 1857. Several variants on the test have been developed, such as the BCA test and the Modified Lowry test. The biuret reaction can be used to assess the concentration of proteins because peptide bonds occur with the same frequency per amino acid in the peptide. The intensity of the color, and hence the absorption at 540 nm, is directly proportional to the protein concentration, according to the Beer–Lambert law. Despite its name, the reagent does not in fact contain biuret . The test is named so because it also gives a p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyanuric Acid
Cyanuric acid or 1,3,5-triazine-2,4,6-triol is a chemical compound with the chemical formula, formula (CNOH)3. Like many industrially useful chemicals, this triazine has many synonyms. This white, odorless solid finds use as a precursor or a component of bleaches, disinfectants, and herbicides. In 1997, worldwide production was 160 000 tonnes.Klaus Huthmacher, Dieter Most "Cyanuric Acid and Cyanuric Chloride" Ullmann's Encyclopedia of Industrial Chemistry" 2005, Wiley-VCH, Weinheim. doi 10.1002/14356007.a08 191 Properties and synthesis Properties Cyanuric acid can be viewed as the cyclic trimer (chemistry), trimer of the elusive chemical species Isocyanic acid#cyanicacid2025-03-05, cyanic acid, HOCN. The ring can readily interconvert between several chemical structure, structures via Lactam#Lactam–lactim tautomerism, lactam–lactim tautomerism. Although the triol tautomer may have aromatic character, the keto form predominates in solution. The hydroxyl (-OH) groups ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Urea
Urea, also called carbamide (because it is a diamide of carbonic acid), is an organic compound with chemical formula . This amide has two Amine, amino groups (–) joined by a carbonyl functional group (–C(=O)–). It is thus the simplest amide of carbamic acid. Urea serves an important role in the cellular metabolism of nitrogen-containing compounds by animals and is the main nitrogen-containing substance in the urine of mammals. ''Urea'' is Neo-Latin, , , itself from Proto-Indo-European ''*h₂worsom''. It is a colorless, odorless solid, highly soluble in water, and practically non-toxic ( is 15 g/kg for rats). Dissolved in water, it is neither acidic nor base (chemistry), alkaline. The body uses it in many processes, most notably metabolic waste#Nitrogen wastes, nitrogen excretion. The liver forms it by combining two ammonia molecules () with a carbon dioxide () molecule in the urea cycle. Urea is widely used in fertilizers as a source of nitrogen (N) and is an important ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Non-protein Nitrogen
Nitrogen's effects on agriculture profoundly influence crop growth, soil fertility, and overall agricultural productivity, while also exerting significant impacts on the environment. Nitrogen is an element vital to many environmental processes. Nitrogen plays a vital role in the nitrogen cycle, a complex biogeochemical process that involves the transformation of nitrogen between different chemical forms and its movement through various environmental compartments such as the atmosphere, soil, water, and living organisms. In its natural state, nitrogen exists primarily as a gas (N2) in the atmosphere, making up about 78% of the air we breathe. Nitrogen finds extensive usage across various sectors, primarily in the agriculture industry, and transportation. Its versatility stems from its ability to form numerous compounds, each with unique properties and applications. Impacts on agriculture Nitrogen is a fundamental nutrient in agriculture, playing a crucial role in plant growth and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ureas
image:Biotin_structure.svg, 220 px, Biotin, a water-soluble B vitamins, B vitamin, is a bicyclic urea. In chemistry, ureas are a class of organic compounds with the formula (R2N)2CO where R = H, alkyl, aryl, etc. Thus, in addition to describing the specific chemical compound urea ((H2N)2CO), urea is the name of a functional group that is found in many compounds and materials of both practical and theoretical interest. Generally ureas are colorless crystalline solids, which, owing to the presence of fewer hydrogen bonds, exhibit melting points lower than that of urea itself. Synthesis Ureas can be prepared many methods, but rarely by direct carbonation, which is the route to urea itself. Instead, methods can be classified according those that assemble the urea functionality and those that start with preformed urea. Assembly of N-substituted urea functionality Phosgenation entails the reaction of amines with phosgene, proceeding via the isocyanate (or carbamoyl chloride) as an i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Isocyanate
In organic chemistry, isocyanate is the functional group with the formula . Organic compounds that contain an isocyanate group are referred to as isocyanates. An organic compound with two isocyanate groups is known as a diisocyanate. Diisocyanates are manufactured for the production of polyurethanes, a class of polymers. Isocyanates should not be confused with cyanate esters and isocyanides, very different families of compounds. The cyanate (cyanate ester) functional group () is arranged differently from the isocyanate group (). Isocyanides have the connectivity , lacking the oxygen of the cyanate groups. Structure and bonding In terms of bonding, isocyanates are closely related to carbon dioxide (CO2) and carbodiimides (C(NR)2). The C−N=C=O unit that defines isocyanates is planar, and the N=C=O linkage is nearly linear. In phenyl isocyanate, the C=N and C=O distances are respectively 1.195 and 1.173 Å. The C−N=C angle is 134.9° and the N=C=O angle is 173.1 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hexamethylene Diisocyanate
Hexamethylene diisocyanate (HDI) is the organic compound with the formula (CH2)6(NCO)2. It is classified as an diisocyanate. It is a colorless liquid. It has sometimes been called HMDI but this not usually done to avoid confusion with Hydrogenated MDI. Synthesis Compared to other commercial diisocyanates, HDI is produced in relatively small quantities, accounting for (with isophorone diisocyanate) only 3.4% of the global diisocyanate market in the year 2000. It is produced by phosgenation of hexamethylene diamine. Applications Aliphatic diisocyanates are used in specialty applications, such as enamel coatings which are resistant to abrasion and degradation by ultraviolet light. These properties are particularly desirable in, for instance, the exterior paint applied to aircraft and vessels. HDI is also sold oligomerized as the trimer or biuret which are used in automotive refinish coatings. Although more viscous in these forms, it reduces the volatility and toxicity. At least 3 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Water
Water is an inorganic compound with the chemical formula . It is a transparent, tasteless, odorless, and Color of water, nearly colorless chemical substance. It is the main constituent of Earth's hydrosphere and the fluids of all known living organisms (in which it acts as a solvent). It is vital for all known forms of life, despite not providing food energy or organic micronutrients. Its chemical formula, , indicates that each of its molecules contains one oxygen and two hydrogen atoms, connected by covalent bonds. The hydrogen atoms are attached to the oxygen atom at an angle of 104.45°. In liquid form, is also called "water" at standard temperature and pressure. Because Earth's environment is relatively close to water's triple point, water exists on Earth as a solid, a liquid, and a gas. It forms precipitation in the form of rain and aerosols in the form of fog. Clouds consist of suspended droplets of water and ice, its solid state. When finely divided, crystalline ice ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemical Test
In chemistry, a chemical test is a qualitative property, qualitative or Quantitative property, quantitative procedure designed to identify, quantify, or characterise a chemical compound or substituent, chemical group. Purposes Chemical testing might have a variety of purposes, such as to: * Determine if, or verify that, the requirements of a specification, regulation, or contract are met * Decide if a new product development program is on track: Demonstrate proof of concept * Demonstrate the utility of a proposed patent * Determine the interactions of a sample with other known substances * Determine the composition of a sample * Provide Technical standard, standard data for other scientific, medical, and Quality assurance functions * Validate suitability for end-use * Provide a basis for Technical communication * Provide a technical means of comparison of several options * Provide evidence in legal proceedings Biochemical tests * Clinistrips quantitatively test for sugar in uri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Allophanic Acid
Allophanic acid is the organic compound with the formula H2NC(O)NHCO2H. It is a carbamic acid, the carboxylated derivative of urea. Biuret can be viewed as the amide of allophanic acid. Treating urea with sodium bicarbonate is claimed to give allophanic acid: :H2NC(O)NH2 + NaHCO3 → H2NC(O)NHCO2H + NaOH Although allophanic acid per se may not have been purified, its conjugate base, H2NC(O)NHCO2−, allophanate is well known. Salts of this anion have been characterized by X-ray crystallography.{{cite journal , doi=10.1080/10610279608233970, title=A Novel Inclusion Compound Consolidated by Host-host and Host-guest Hydrogen Bonding: (2-hydro-xyethyl)trimethylammonium Ions Included in a Channel Host Lattice Built of Urea Molecules and Allophanate Ions, year=1996, last1=Li, first1=Qi, last2=Mak, first2=Thomas C. W., journal=Supramolecular Chemistry, volume=8, pages=73–80 The allophanate anion is the substrate for the enzyme allophanate hydrolase In enzymology, an allophan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
