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Topic: Zn + EDTA  (Read 1864 times)

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Offline duende

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Zn + EDTA
« on: April 30, 2014, 11:00:23 AM »
Hi everybody,
I'm a student of Biology. I'd like to ask you something. I grew my microalgae in a culture medium containing - among other things - Na2EDTA 8.29 µM, Na2EDTA 6.56 µM and ZnSO4 254 nM. How can I calculate the [Zn]
bioavailable and not complexed with EDTA? Are there programs to do that?
Thanks guys!

duende

Offline Borek

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Re: Zn + EDTA
« Reply #1 on: April 30, 2014, 11:29:38 AM »
You should calculate concentration of EDTA4- from pH, then Zn2+ can be calculated from the stability constant (and known total concentrations of EDTA and Zn). Not a trivial task, but definitely doable.

Na2EDTA 8.29 µM, Na2EDTA 6.56 µM

So which one it is?
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Offline Big-Daddy

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Re: Zn + EDTA
« Reply #2 on: May 09, 2014, 03:13:00 PM »
As your Zn2+ is consumed, though, more of the complexed form will shift back to Zn2+. As far as I can see, if you want a reasonable quantitative treatment of this you need to know all the reactions - including some idea of how to model the biological processes you're about to make happen. Otherwise, once "all" your free Zn2+ is consumed, it'll simply be replaced.

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