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CH3041
METAL SPECIATION
• A significant part of the total soluble metal content in natural waters is found as metal complexes with the metal ions bound to organic ligands.
•
  Cu    Oceans   > 99%
  Zn    Oceans   > 99%    Rivers   » 14%
Hg    Rivers     2 - 89%
Trace Metal Speciation
• Identification of the metal species present in soln is important in toxicology. 
eg. free Cu2+ very toxic;  Cu2+(humic)n non-toxic
• Electrochemistry is the analytical method most often used in speciation studies   E1/2