It appears that ferric chloride is getting hydrolysed, hence not extracted by diethylether, try to extract the same by increasing the same by addition of hydrochloric acid to improve extraction of ferric chloride

Would the method in Matthews et al 2001 (EPSL 192: 81-92) work for you.

http://www.sciencedirect.com/science/article/pii/S0012821X01004320

Another option, if the substances dissolved in the aqueous phase can handle high normality acid, is to used diisopropyl ether extraction from 6N HCl. This works for us in our lab, although one has to be diligent when using ethers that can over time oxidize to peroxides.

Hi Ken,

I had this problem about 10 year ago but in that case I did not want Fe(III) to phase transfer. A promising way of achieving this is phase transfer extraction. For the ions you mention you need to work in a strong acidic medium to prevent hydrolysis. secondly you need an anion that generates complexes with this anion that are soluble in the organic phase. Thirdly, the difference in complex formation constants of the anion with Fe(II) vs Fe(III) must be large enough in favor of the Fe(III) complex. Thus something like 6M HCl might achieve this. With other ligands the problem is that in such strong acidic media the ligand remains in the acidic form which is not active. Therefore ligands of strong acids can work.

Alternatively, you can start in acid (HCl for example), add a Na- or K-ligand salt with favorable complex formation constants (few Molar, see above) and slowly neutralize the solution while stirring. This prevents precipitation and forms the desired complexes. Then add organic solvent and start extracting.

Another thing is the choice of solvent. I do not know whether diethylether is the right choice, that you have to experience with. A reference I can recommend you is: Starks, C. M., Liotta, C. L., and Halpern, M., “Phase transfer catalysis”, G, Chapman & Hall, 1994.

Thanks for all, but I ask Mr. Ken if he succeeded for extract of ferric chloride from aqueous solution in the presence of ferrous ions by diisopropyl ether in his laboratory. If so; please send me the procedure. Thank you for cooperation

Dear Theia'a Al-Sabha, the procedure is as follows (sorry I have no reference, this was passed to me 25 years ago and I believe it is a fairly common procedure). My goal is to remove Fe+3 from a U analyte because Fe+3 interferes with the analysis. We have the material dissolved in 3 to 4 ml of 6N HCl and use an equal volume of di-isopropyl ether (which we test every 6 months with peroxide test strips to make sure it is safe to use). The volumes we deal with are too small for a separatory funnel so we do the mixing and settling with a glass pipette. After gently mixing 5-10 times the yellow color of the HCl usually goes away completely. Sometimes a second extraction is needed (another aliquot of ether on the same HCl solution). The ether solution (with the Fe3+) is then evaporated and Fe+3 is dissolved in the solution of interest. One can evaporate the ether in the presence of dilute HCl to dissolve the Fe+3, and purify with cation resin if desired.

Dear Ken, thank you very much and I shall do the same procedure and hope to be succeeded.