Inorganic affinity

Figures 2-5 present examples of graphic representations of the organic-inorganic affinities of several elements in coals. A larger number...

Many data on trace elements in coal are included in the chapter. The emphasis is on the geochemistry of the trace elements, with discussions of the concentration levels of trace elements in coals, the organic (or inorganic) affinities of the trace elements, and the geochemical controls of associations of elements. This and the following significant review article are contained within a single volume. 

The relationship between the concentration of an element in "whole" coal and the ash content can be used as a guide to the affinity of that element for, or incorporation in, the mineral matter or the carbonaceous material. If the concentration of an element increases with increasing ash content that element is presumed to be associated with the inorganic species that form ash, or in other words may be said to have an inorganic affinity. If the concentration shows no correlation with ash content, that element would be said to have an organic affinity. Linear least squares correlation coefficients were calculated for the concentrations of 39 elements... 

Inorganic affinity by strong positive correlation with ash content. 

Many of the inorganic oxoacids are strong (i.e. have negative PX3 values) in aqueous solution. But, as we have seen, use of a solvent with a lower proton affinity than water (for example pure ethanoic (acetic) acid makes it possible to differentiate between the strengths of these acids and measure pX values. The order of strength of some typical oxoacids is then found to be (for H X -> H , X- + H") ... 

For a radionuclide to be an effective oceanic tracer, various criteria that link the tracer to a specihc process or element must be met. Foremost, the environmental behavior of the tracer must closely match that of the target constituent. Particle affinity, or the scavenging capability of a radionuclide to an organic or inorganic surface site i.e. distribution coefficient, Kf, is one such vital characteristic. The half-life of a tracer is another characteristic that must also coincide well with the timescale of interest. This section provides a brief review of the role of various surface sites in relation to chemical scavenging and tracer applications. 

Another type of detoxication involves the production of cysteine conjugates, which are readily excreted. (Again, organomercury compounds show their affinity for -SH groups). Methyl mercuric cysteine is an important biliary metabolite in the rat and is degraded within the gut (presumably by microorganisms) to release inorganic mercury (see IAEA Report 137, 1972). 

There is good agreement that the two high-affinity Ca sites are within = 10 A of each other (Table II) [132,390,404-409], Their localization within the bilayer is supported by the observation [130,131] that site-specific mutagenesis of several amino acids within the putative transmembrane helices interferes with Ca binding and with the Ca -dependent phosphorylation of the enzyme by ATP, but has no effect on the Ca -independent phosphorylation by inorganic phosphate. 

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