Sulphur organic forms

Organic forms of mercury, such as methyl mercury, which caused the Minamata disease, are different from the other two forms in that they are very soluble in fat and therefore readily able to enter the brain and nervous system (see p. i8). Again the interaction with natural sulphur-containing substances in the body is important. A product of this interaction mimics an amino acid for which a specific system of transport into the brain exists. So, rather like the Spartans in the Trojan horse, mercury enters the brain, and once there it can disrupt essential processes. 

In other reactions, cyanide functions rather simply as a nucleophile. The organic examples are numerous. Reaction at sulphur to form thiocyanate is a convenient inorganic example this occurs with thiosulphate tetrathionate and pentathionate, and with sulphur (Sg and Sg) itself The reactions which... 

Many other sulphur-organic reagents have found use in the determination of Ru, e.g., rubeanic acid [44] and unithiol [45]. 2-Thiobarbituric acid has been used in a method based on derivative spectrophotometry [46]. Dithizone (at 85 C) forms with Ru a complex extractable into CHCI3 [47]. 

Sulphur organic compounds are very sensitive to pH (Fig. 66). As the acidic form absorbs differently from the basic one, it is possible to calculate the pKa value of these compounds. The example of thiophenol is given, and the estimated pKa value is close to 6.2 (Fig. 66). 

Alcohol reacts with organic acids and forms ethereal salts (esters), the reaction being facilitated by the presence of a dehydrating agent. For example, alcohol and acetic acid, when warmed together in the presence of sulphuric acid, form ethyl acetate —... 

The use of acidifiers containing inorganic acids in-feed has become popular due to their relatively cheaper costs compared to organic forms, and weaner diets including these acids are considered a low cost option. To examine the relative efficacy of inorganic acids, studies were carried out using hydrochloric acid, sulphuric acid and... 

Sulphur Bacteria.—A group of organisms that obtain energy by the oxidation of HgS into H2SO4, by means of a chain of reactions. Some occur in soil, and may account for the eonversion of unavailable sulphur into forms assimilable by higher plants. 

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