Biological availability metalloids

The detection of metals and metalloids no longer present major analytical problems. The instrumental techniques are both sensitive and specific for most elements. In contrast, the usual techniques for the detection of biological molecules respond to functional groups and consequently, they are relatively non-specific. However, it is possible to apply more specific methods when some information is available about the likely identity of the molecule. 

In 1968 we discovered that methylcobalamin was capable of transferring a methyl-carbanion to mercuric salts in aqueous solutions. This initial discovery opened the door to a study of reactions between methylcobalamin and a number of metal and metalloid ions. Methyl-transfer in biological systems naturally depends on the co-enzymes which are available to perform this function. Three co-enzymes have been found which are capable of the transfer of methyl groups (1) methylcorrinoid derivatives,... 

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