Mg-containing organic compounds

Mg-containing organic compounds 5. Summary and Outlook Acknowledgements... 

Table 3 gives a compilation of the experimentally derived solid-state Mg NMR parameters (Cq, and 5jso) reported to date for various Mg-containing organic compounds. Similarly to what was done before for the inorganic compounds, the special methods used to improve sensitivity or resolution in the performed experiments are mentioned in the table, as well as the cases where there are inconsistencies between results achieved by different researchers. 

TABLE 3 Experimental NMR parameters for Mg-containing organic compounds... 

The method has been used successfully to analyse a number of sulphur-containing organic compounds, including those that contain fluorine, chlorine, nitrogen and oxygen. The mean relative standard deviation is 0.37%. A complete analysis takes about 20 min. The sulphur detection limit is 0.05 mg. Although some conventional methods, such as the lamp method, are capable of measuring lower concentrations, there are indications that the method under review will eventually be suitable for the simultaneous determination of sulphur and some other elements. 

A 101.3-mg sample of an organic compound known to contain Cl is burned in pure O2 and the combustion gases collected in absorbent tubes. The tube used to trap CO2 increases in mass by 167.6 mg, and the tube for trapping H2O shows a 13.7-mg increase. A second sample of 121.8 mg is treated with concentrated HNO3 producing CI2, which subsequently reacts with Ag+, forming 262.7 mg of AgCl. Determine the compound s composition, as well as its empirical formula. 

Gas and Leachate Movement and Control Under ideal conditions, the gases generated from a landfill should be either vented to the atmosphere or, in larger landfills, collected for the production of energy. Landfills with >2.5 miUion cubic meters of waste or >50 Mg/y NMOC (nonmethane organic compounds) emissions may require landfill-gas collection and flare systems, per EPA support WWW, CFR 60 Regulations. The leachate should be either contained within the landfill or removed for treatment. 

About half of the dissolved organic carbon may appear in humic or fulvic acids. These are high-molecular weight organic compounds of a composition which is somewhat uncertain. They contain aromatic hydroxyl and carboxyl groups which have the ability to bind to metal ions. Rivers and estuaries typically contain 10 mg/liter of acid with an exchange capacity of 5-10 mmol/g, mainly due to carboxylic... 

There are distinct structural types of organic compounds containing metals and metalloids. The first contain covalent carbon-metal bonds and are strictly organometallic compounds, for example, the alkylated compounds of Hg, Sn and Pb, and of Li, Mg, and A1 (and formerly Hg), which have been extensively used in laboratory organic synthesis, and A1(C2H5)3 that is a component of the... 

Hercules Chemical produced an acidic organic waste derived from the manufacture of dimethyl terphthalate, which is used in the production of synthetic liber. The average dissolved organic carbon concentration was about 7100 mg/L and included acetic acid, formic acid, p-toluic acid, formaldehyde, methanol, terphthalic acid, and benzoic acid. The pH ranged from 3.5 to 4.0. The waste also contained traces (less than 0.5 mg/L) of 11 other organic compounds, including dimethyl phthalate, a listed hazardous waste. 

Retorting of oil shales to produce shale oil results in wastes (condensate water and solid semi-coke residue) that are heavily contaminated with organic compounds, especially phenolic compounds. Semi-coke leachate is typically alkaline (Kundel Liblik 2000) and can contain several hundred mg/L phenol in Estonia, in addition to potentially toxic heavy metals and trace elements, for example, As, B, F, Mo, and Se, which might be mobilized during leaching by water. Volatilization of phenols from leachate lagoons can also impact atmospheric quality. 

---