Tin is a toxic metal that can accumulate in human body. Tin
exists in two oxidation states. These are divalent tin Sn(II) and tetravalent
tin Sn(IV) (Blunden &Wallace, 2003). These forms depend
on pH. At pH > 2, Sn(II) forms Sn(OH)2, which have low solubility
under anoxic conditions whereas Sn(IV) presents in form of
Sn(OH)4 under oxic conditions at lower pHs than 8.0 (Kassoufab,
Chebiba, Lebbosc, & Ouainia, 2013)