[diskjoncter]

Hi Guys,

I'm just wondering how calcium disodium EDTA ionizes during oral chelation ?

Is the final level of Ca++ and Na+ rises in the "solution" if there's other cations in contact ?

The EDTA----  attracts what kind of cations (+, ++, +++, ++++) preferentially ?

Since EDTA is used to chelate Metals, I suspect that we find something like M(EDTA) or M(EDTA)++, what else, what next ?

Thank you for your help, very appreciated.

[Borek]

2Na⁺ + CaY^2-

[diskjoncter]

Thanks but what are the possibilities with the chelation then?

[Borek]

I am not sure what you are asking about. Final charge of the complex will depend on the charge of the central cation. My bet is that the CaY^2- is intended to react with other cations doing something like

CaY^2- + Meⁿ⁺ MeY^n-4 + Ca²⁺

[diskjoncter]

Yes, that was the step I'm looking for, there's some misunderstsandings with EDTA acid and EDTA calcium disodium salt, for example:
you can read in some internet places that EDTA calcium disodium might lead to hypocalcemia, wich is not obviously the case with that Ca²⁺ around but EDTA acid might conduct to hypocalcemia...

My chemistry knowledge is a bit rusty so my English, sorry 

MeY^n-4 would get which Me preferentially ? It is said that it's good to sequestrate Pb, is there a scale of "susceptibility" for Me ?

[Borek]

MeY^n-4 would get which Me preferentially ? It is said that it's good to sequestrate Pb, is there a scale of "susceptibility" for Me ?

Depends on the stability constants, so it has to be compared for each metal separately - there is no simple rule.

[diskjoncter]

Thank you for your help, so in short EDTA calcium disodium loses 2Na⁺ and Ca²⁺ and bonds to a Me cation,
 in the end the seric level of Na⁺ and Ca²⁺ rise both.