Inorganic species extraction

Apart from ammonia, some other inorganic species extracted by hquid membranes are strong acids like nitric acid and thiocyanate ions from aqueous solutions using carrier-mediated coupled transport process. 

Pyrolysis. Heating in the absence of oxygen releases moisture at low temperatures, carbon dioxide at temperatures >200° C, and a variety of gaseous products at very high temperatures. Acid washing of the raw coal is used to remove extractable cations, followed by treatment with selected cations. Yields of CO2, CO, CH, H2, and H2O depend on the amounts of inorganic species in the coal (42). 

In order to suppress interferences due to the presence of inorganic species and reliably determine the proteinaceous composition of the sample, a clean-up step has often been introduced in the analytical procedure. This step may include the extraction of the proteinaceous matter by an ammonia solution [8], the use of a cation-exchange resin [8,55], a chelating agent [9,41,44], the use of a Cig resin or the use of barium chloride solution to suppress sulfates [10,81,82]. Table 9.1 reports the methods used to overcome such problems. 

As in the other -omics, analyses may be directed at a specific metabolite, at all metabolites in a given system in a shot-gun approach, or at accessible groups of molecules in profiling experiments. In that also the technology varies. In addition, the chemistry of different metabolites is very heterogeneous since it involves hydrophobic lipids, hydrophilic carbohydrates, ionic inorganic species, and other secondary natural products and already the choice of solvent in metabolite extraction dictates which types of molecules will be present (Fig. 10.8). Therefore, total metabolome profiling is not possible, because no analytical method will be able to accommodate all the different molecule classes at once. 

Inorganic species in soil are generally extracted with either water or an acid solution typically containing hydrochloric acid. Various other components that aid either in the solubilization, extraction, or stabilization of extracted inorganics, such as chelates, are also often added during the extraction process. Basic extractions are not as commonly used as are acid extractions with a few notable exceptions. The use of ion exchange resins to extract ions from soil is well established. 

Inorganic species Blow down extract with nitrogen to 50 pi... 

Pamukcu, S., Weeks, A. and Wittle, J. K. (1997) Electrochemical Extraction and Stabilization of Selected Inorganic Species in Porous Media, Journal of Hazardous Materials, Special Issue on Electrochemical Decontamination of Soil and Water, Edited by Y.B. Acar and A.N. Alshawabkeh, V. 55, No s. 1—3, pp. 1-22. 

A field method of pre-concentration and preservation of organo-mercury species extracted from water was described (Jian and McLeod, 1992). Acidified water samples were passed through microcolumns packed with sulfhydryl cotton. The packing retained organo-mercury species, but not inorganic mercury. The contents were analysed later in a laboratory. 

As late as 1987, McDougall and Fleming [27], whose interests rested primarily in the extraction of gold by activated carbons, commented that the adsorption of organic and inorganic species onto carbon may occur by several mechanisms, the unraveling of which, especially in the extraction of certain metal complexes from. solution, is extremely difficult. ... 

The extraction of inorganic species such as Fe [146], and Cu, Pb, As, Se, Hg and Cd [172], from soils was investigated on a pilot plant scale with a view to developing an industrial-scale method for decreasing allowed levels of the metals used to manufacture cement. To this end, kinetic curves for the extraction rate were used that allowed the time... 

An extraction is frequently more attractive than a precipitation method for separating inorganic species. The processes of equilibration and separation of phases in a separatory funnel are less tedious and time consuming than conventional precipitation, filtration, and washing. 

A number of inorganic species can be separated by extraction with suitable solvents. For example, a single ether extraction of a 6 M hydrochloric acid solution will cause better than 50% of several ions to be transferred to the organic phase included among these are iron(III), antimony(V), titanium(III), gold(IIl), molybde-num(VI), and tin(IV). Other ions, such as aluminum(IIl) and the divalent cations of cobalt, lead, manganese, and nickel, are not extracted. 

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