Natural organic compounds

Additional information is required to determine what is causing this net removal. In the case of iron, research has demonstrated that its solubility decreases with increasing salinity leading to the formation of two types of solids (1) iron oxide minerals, and (2) organic floes. Some iron is also removed by uptake as a micronutrient by plankton. The floes form from the co-precipitation of iron with the high-molecular-weight dissolved organic compounds naturally present in river water. 

Organic compounds, natural, fossil or anthropogenic, can be used to provide a chemical mass balance for atmospheric particles and a receptor model was developed that relates source contributions to mass concentrations in airborne fine particles. The approach uses organic compound distributions in both source and ambient samples to determine source contributions to the airborne particulate matter. This method was validated for southern California and is being applied in numerous other airsheds. ... 

Horvath CG, Lipsky SR. Use of hquid ion exchange chromatography for separation of organic compounds. Nature 211, 748-749, 1966. 

Platt, U., G. Le Bras, G. Poulet, J. P. Burrows, and G. Moortgat, Peroxy Radicals from Nighttime Reaction of NOj with Organic Compounds, Nature, 348, 147-149 (1990). 

A high molecular weight organic compound, natural or synthetic, whose structure can be represented by a repeated small unit, the monomer (e.g., polyethylene, isoprene and cellulose). Synthetic polymers are formed by the addition or condensation polymerization of monomers. If two or more different monomers are involved, a copolymer is obtained. Some polymers can be rubbers and some can be plastics. Plastics which are also high polymers can include both natural, or synthetic products but exclude rubber whether natural or synthetic. At some stage in its manufacture every plastic is capable of flowing under heat and pressure into the desired final shape. 

Singh H., Chen Y., Staudt A., Jacob D., Blake D., Heikes B., and Snow J. (2001) Evidence from the Pacific troposphere for large global sources of oxygenated organic compounds. Nature 4111, 1078-1081. 

Perakis S. S. and Hedin L. O. (2002) Nitrogen loss from unpolluted South American forests mainly via dissolved organic compounds. Nature (London) 415(6870), 416-419. 

C 13. CoRTis-JoNES, B. Gel filtration of organic compounds. Nature 191, 272 (1961). 

Chemists like to make model compounds to see whether their ideas about mechanisms in nature can be reproduced in simple organic compounds. Nature s reducing agent is NADPH and, unlike NaBH4, it reduces stereopecifically (p. 1150 of the textboold. A model for a proposed mechanism uses a much simpler molecule with a close resemblance to NADH. Acylation and treatment with Mg(ll) causes stereospecific reduction of the remote ketone. Suggest a mechanism for this stereochemical control. How would you release the reduced product ... 

Maple Avenue Shrewsbury, MA 01545 Fax 508-752-4123 E-mail glsyn glsynthesis.com Internet site www.gls5mthesis.com custom synthesis small organic compounds, natural products, heterocycles, nucleosides and nucleotides... 

The subject of another investigation in the nature of archaeological amber samples (pendants found in the upper reaches of the Western Dvina River) was the fact that a chunk of resinous material found by local residents in the same location was a candidate for the raw material used to make these pendants. Py-GC/MS analysis revealed that all the pendants were made of Baltic amber, and the raw material represented a totally different class of organic compounds — natural gums. Figure 6.10 shows two pyrograms (A for the Baltic amber with a strong peak of succinic anhydride and B for the natural gum with a very characteristic peak of furfural). 

In every organic compound (natural or synthesized from natural sources), the will result in a peak that is one mass number greater than the mass of the molecular ion. This C-containing peak is generally designated as (M + 1). For example, with methane, CH4, the MW is 16, assuming that carbon has an atomic weight of 12 (i.e., = 12 + 4 = 16). Let the abundance of this peak be 100. 

Polymer. A high molecular weight organic compound, natural or synthetic, whose structure can be represented by a repeated small unit, the monomer. Synthetic polymers are formed by addition or condensation polymerization of monomers. When two or more monomers are involved, the product is called a copolymer. 

Narymbetov, B. et al. Origin of ferromagnetic exchange interactions in a fiiUerene-organic compound. Nature 407, 883-885, 2000. 

Hutchings, G., Heneghan, C. and Taylor, S. (1996). Uranium-oxide-based Catalysts for the Destmction of Volatile Chloro-organic Compounds, Nature, 384, pp. 341-343. 

Hutchings, G.J., Heneghan, C.S., Hudson, I.D., and Taylor, S.H. Uranium-oxide-based catalysts for the destruction of volatile chloro-organic compounds. Nature 1996, 384, 341-343. 

Bennett PC, Siegel DI (1987) Increased solubility of quartz in water due to complexing by organic compounds. Nature 326 684-686... 

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