- 関
- catabolite、degradation product
WordNet
- a chemical substance formed as a result of a chemical reaction; "a product of lime and nitric acid"
- a consequence of someones efforts or of a particular set of circumstances; "skill is the product of hours of practice"; "his reaction was the product of hunger and fatigue"
- an artifact that has been created by someone or some process; "they improve their product every year"; "they export most of their agricultural production" (同)production
- a quantity obtained by multiplication; "the product of 2 and 3 is 6" (同)mathematical product
- (chemistry) separation of a substance into two or more substances that may differ from each other and from the original substance (同)decomposition reaction, chemical decomposition reaction
- in a decomposed state (同)disintegration
- (biology) the process of decay caused by bacterial or fungal action (同)rot, rotting, putrefaction
- the analysis of a vector field (同)vector decomposition
PrepTutorEJDIC
- 『産物』;製品 / (…の)結果,帰結《+『of』+『名』(do『ing』)》 / (数の)積 / (化学の)生成物
- 分解 腐敗 変質
Wikipedia preview
出典(authority):フリー百科事典『ウィキペディア(Wikipedia)』「2014/04/10 17:51:05」(JST)
[Wiki en表示]
Chemical decomposition, analysis or breakdown is the separation of a chemical compound into elements or simpler compounds. It is sometimes defined as the exact opposite of a chemical synthesis. Chemical decomposition is often an undesired chemical reaction. The stability that a chemical compound ordinarily has is eventually limited when exposed to extreme environmental conditions like heat, radiation, humidity or the acidity of a solvent. The details of decomposition processes are generally not well defined, as a molecule may break up into a host of smaller fragments. Chemical decomposition is exploited in several analytical techniques, notably mass spectrometry, traditional gravimetric analysis, and thermogravimetric analysis.
A broader definition of the term decomposition also includes the breakdown of one phase into two or more phases.[1]
There are three broad types of decomposition reactions: thermal, electrolytic and catalytic.[citation needed]
Contents
- 1 Reaction formula
- 2 See also
- 3 References
- 4 External links
Reaction formula
The generalized reaction for chemical decomposition is:
- AB → A + B with a specific example being the electrolysis of water to gaseous hydrogen and oxygen:
- 2 H2O(I) → 2 H2 + O2
Additional examples
An example of spontaneous decomposition is that of hydrogen peroxide, which will slowly decompose into water and oxygen:
- 2 H2O2 → 2 H2O + O2
Carbonates will decompose when heated, a notable exception being that of carbonic acid, H2CO3. Carbonic acid, the "fizz" in sodas, pop cans and other carbonated beverages, will decompose over time (spontaneously) into carbon dioxide and water
- H2CO3 → H2O + CO2
Other carbonates will decompose when heated producing the corresponding metal oxide and carbon dioxide. In the following equation M represents a metal:
- MCO3 → MO + CO2
A specific example of this involving calcium carbonate:
- CaCO3 → CaO + CO2
Metal chlorates also decompose when heated. A metal chloride and oxygen gas are the products.
- 2 MClO3 → 2 MCl + 3 O2
A common decomposition of a chlorate to evolve oxygen utilizes potassium chlorate as follows:
- 2 KClO3 → 2 KCl + 3 O2
See also
- Analytical chemistry
- Thermal decomposition
References
- ^ IUPAC, Compendium of Chemical Terminology, 2nd ed. (the "Gold Book") (1997). Online corrected version: (2006–) "decomposition".
External links
UpToDate Contents
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English Journal
- ReaxFF molecular dynamics simulations of the initial pyrolysis mechanism of unsaturated triglyceride.
- Zhang Z1, Yan K, Zhang J.Author information 1College of Mining Engineering, Taiyuan University of Technology, No.79 West Yingze Street, Taiyuan, Shanxi, People's Republic of China, 030024, donaldzhang@foxmail.com.AbstractTo understand the impact of C = C double bonds in acyl chains of unsaturated triglycerides on the reaction mechanism and product composition in their initial pyrolysis process, ReaxFF molecular dynamics simulations were carried out using a molecular model, trilinolenin, at temperatures of 2000, 2250, and 2500 K. Analyses indicated that the observed pyrolysis mechanisms of unsaturated triglyceride are nearly identical to the saturated triglyceride, and the pyrolysis products also include alkanes, alkenes, alkadienes, aromatics, oxygenated species, CO2, and H2. The formation of intermediates and products is a sequential process. Three C-O bonds in trilinolenin molecule are usually successive dissociated first, leading to the formation of unsaturated C3H5 (·) radical and straight-chain C18H29O2 (·) (RCOO(·)) radicals. Following that, the deoxygenated alkenyl chain is produced through decarboxylation of RCOO · radicals with consequent release of CO2. The resulting hydrocarbon radicals undergo a variety of disproportionation, isomerization, and hydrogen-transfer reactions, yielding straight and branched-chain hydrocarbons. It was found that the scission of C-O bond and decarboxylation should preferentially occur before the cleavage of the C-C bond β to the C = C bond in the initial decomposition process of unsaturated trilinolenin. In addition, the formation of cyclic hydrocarbons could proceed through intramolecular cyclization mechanisms, including non-radical electrocyclic, biradical cyclization and cyclization of alkenyl radical, which are inconsistent with previously proposed bimolecular Diels-Alder addition mechanisms. More rapid pyrolysis of trilinolenin would occur at higher temperatures without significantly affecting the apparent reaction mechanisms of trilinolenin pyrolysis in the considered temperature range. Aromatic ring structures are observed to be stable after formation and do not decay within the 500 ps simulation period.
- Journal of molecular modeling.J Mol Model.2014 Mar;20(3):2127. doi: 10.1007/s00894-014-2127-6. Epub 2014 Feb 25.
- To understand the impact of C = C double bonds in acyl chains of unsaturated triglycerides on the reaction mechanism and product composition in their initial pyrolysis process, ReaxFF molecular dynamics simulations were carried out using a molecular model, trilinolenin, at temperatures of 2000,
- PMID 24567153
- Application of independent component analysis on Raman images of a pharmaceutical drug product: Pure spectra determination and spatial distribution of constituents.
- Boiret M1, Rutledge DN2, Gorretta N3, Ginot YM4, Roger JM3.Author information 1Technologie Servier, 27 rue Eugène Vignat, 45000 Orléans, France. Electronic address: mathieu.boiret@fr.netgrs.com.2AgroParisTech, UMR 1145 Ingénierie Procédés Aliments, rue Claude Bernard, F-75005 Paris, France.3Irstea, UMR ITAP 361, Avenue Jean-François Breton, 34033 Montpellier, France.4Technologie Servier, 27 rue Eugène Vignat, 45000 Orléans, France.AbstractIndependent component analysis (ICA) was used as a blind source separation method on a Raman image of a pharmaceutical tablet. Calculations were performed without a priori knowledge concerning the formulation. The aim was to extract the pure signals from the initial data set in order to examine the distribution of actives and major excipients within the tablet. As a method based on the decomposition of a matrix of mixtures of several components, the number of independent component to choose is a critical step of the analysis. The ICA_by_blocks method, based on the calculation of several models using an increasing number of independent components on initial matrix blocks, was used. The calculated ICA signals were compared with the pure spectra of the formulation compounds. High correlations between the two active principal ingredient spectra and their corresponding calculated signals were observed giving a good overview of the distributions of these compounds within the tablet. Information from the major excipients (lactose and avicel) was found in several independent components but the ICA approach provides high level of information concerning their distribution within the tablet. However, the results could vary considerably by changing the number of independent components or the preprocessing method. Indeed, it was shown that under-decomposition of the matrix could lead to better signal quality (compared to the pure spectra) but in that case the contributions due to minor components or effects were not correctly identified and extracted. On the contrary, over-decomposition of the original dataset could provide information about low concentration compounds at the expense of some loss of signal interpretability for the other compounds.
- Journal of pharmaceutical and biomedical analysis.J Pharm Biomed Anal.2014 Mar;90:78-84. doi: 10.1016/j.jpba.2013.11.025. Epub 2013 Dec 1.
- Independent component analysis (ICA) was used as a blind source separation method on a Raman image of a pharmaceutical tablet. Calculations were performed without a priori knowledge concerning the formulation. The aim was to extract the pure signals from the initial data set in order to examine the
- PMID 24333706
- Stability Analysis of Glutamic Acid Linked Peptides Coupled to NOTA through Different Chemical Linkages.
- Lang L1, Ma Y, Kiesewetter DO, Chen X.Author information 1Laboratory of Molecular Imaging and Nanomedicine (LOMIN), National Institute of Biomedical Imaging and Bioengineering (NIBIB), National Institutes of Health (NIH) , 31 Center Drive, Building 31, 1C22, Bethesda, Maryland 20892-2281, United States.AbstractGlutamic acid is a commonly used linker to form dimeric peptides with enhanced binding affinity than their corresponding monomeric counterparts. We have previously labeled NOTA-Bn-NCS-PEG3-E[c(RGDyK)]2 (NOTA-PRGD2) [1] with [18F]AlF and 68Ga for imaging tumor angiogenesis. The p-SCN-Bn-NOTA was attached to E[c(RGDyK)]2 [2] through a mini-PEG with a thiourea linkage, and the product [1] was stable at radiolabeling condition of 100 °C and pH 4.0 acetate buffer. However, when the same p-SCN-Bn-NOTA was directly attached to the α-amine of E[c(RGDfK)]2 [3], the product NOTA-Bn-NCS-E[c(RGDfK)]2 [4] became unstable under similar conditions and the release of monomeric c(RGDfK) [5] was observed. The purpose of this work was to use HPLC and LC-MS to monitor the decomposition of glutamic acid linked dimeric peptides and their NOTA derivatives. A c(RGDyK) [6] and bombesin (BBN) [7] heterodimer c(RGDyK)-E-BBN [8], and a dimeric bombesin E(BBN)2 [9], both with a glutamic acid as the linker, along with a model compound PhSCN-E[c(RGDfK)] [10] were also studied. All the compounds were dissolved in 0.5 M pH 4.0 acetate buffer at the concentration of 1 mg/mL, and 0.1 mL of each sample was heated at 100 °C for 10 min and the more stable compounds were heated for another 30 min. The samples at both time points were analyzed with analytical HPLC to monitor the decomposition of the heated samples. The samples with decomposition were further analyzed by LC-MS to determine the mass of products from the decomposition for possible structure elucidation. After 10 min heating, the obvious release of c(RGDfK) [5] was observed for NOTA-Bn-NCS-E[c(RGDfK)]2 [4] and Ph-SCN-E[c(RGDfK)] [10]. Little or no release of monomers was observed for the remaining samples at this time point. After further heating, the release of monomers was clearly observed for E[c(RGDyK)]2 [2], E[c(RGDfK)]2 [3], c(RGDyK)-E-BBN [8], and E(BBN)2 [9]. No decomposition or little decomposition was observed for NOTA-Bn-NCS-PEG3-E[c(RGDyK)]2 [1], PEG3-E[c(RGDyK)]2 [11], NOTA-E[c(RGDyK)]2 [12], and NOTA-PEG3-E[c(RGDyK)]2 [13]. The glutamic acid linked dimeric peptides with a free α-amine are labile due to the neighboring amine participation in the hydrolysis. The stability of peptides could be increased by converting the free amine into amide. The instability of thiourea derivatives formed from α-amine was caused by participation of thiol group derived from thiourea.
- Molecular pharmaceutics.Mol Pharm.2014 Feb 24. [Epub ahead of print]
- Glutamic acid is a commonly used linker to form dimeric peptides with enhanced binding affinity than their corresponding monomeric counterparts. We have previously labeled NOTA-Bn-NCS-PEG3-E[c(RGDyK)]2 (NOTA-PRGD2) [1] with [18F]AlF and 68Ga for imaging tumor angiogenesis. The p-SCN-Bn-NOTA was atta
- PMID 24533430
Japanese Journal
- Mn含有鉱石を用いたダイオキシン前駆物質分解技術の基礎検討
- Low-temperature carbothermal nitridation of boron oxide induced by networked carbon structure
Related Links
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★リンクテーブル★
[★]
- 英
- catabolite、degradation product、decomposition product
- 関
- 異化産物、カタボライト、分解生成物、分解産物
[★]
- 英
- catabolite、degradation product、decomposition product
- 関
- 異化産物、カタボライト、分解生成物、分解物
[★]
- 関
- decomposition product、degradation product
[★]
- 関
- catabolite、decomposition product
[★]
- 英
- degradation product、decomposition product
- 関
- 分解産物、分解物
[★]
- 関
- breakdown、catabolize、catabolized、crack、decompose、degradation、degrade、disassemble、disassembly、disintegrate、disintegration、putrefaction、putrefactive、resolve、rot
[★]
- 関
- accomplishment、achievement、consequence、outcome、output、result、resultant、sequence