[Reddart]

I am looking to reduce the amount of iron (other trace metals as well) in my product, which already undergoes an organic/aqueous wash step. Can this be accomplished using edta in the aqueous wash? or perhaps a more specific iron chelator?

[Babcock_Hall]

Do you know the oxidation state of the iron?  That might affect which chelator is best.  My prediction is that EDTA will work, but I don't have any references handy.  From memory commercial EDTA itself is not necessarily entirely free of trace metal ions; therefore, one might have to give some thought to how best to prepare it, depending on how stringent the needs of the experiment are.  I used to prepare EDTA solutions starting from its free acid form, but obviously the KOH that I used might also have been a source of trace metal ions.

In ancient times I used to keep a manila folder with photocopies of papers on the general subject of removal of trace metal ions, although some of the processes that I found were for pulling the trace metal ion out of aqueous solutions and into an organic layer, something that a biochemist would need to do.

[Reddart]

The range that I'm looking to remove is from the 100's of ppm down to the ~10's ppm for Fe, so super low metal removal is not required. I suspect it may be coming from a strong acid source (that is used in the reaction) that I am unfortunately stuck with, for now.

I'll try a few extraction experiments to see if that helps.

[Babcock_Hall]

I chatted with a friend who suggested disodium EDTA at less than saturating concentration.  Sodium thiocyanate is another option.

[phth]

Rochelle's salt saturated aqueous solution to wash? (potassium sodium tartrate)