Chemical Forums
Chemistry Forums for Students => Organic Chemistry Forum => Topic started by: ldv1519 on April 06, 2012, 06:14:49 PM
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I need to dissolve EDTA in a non-aqueous solution. I tried to follow a protocol described in: Scott et al., 1978, "Demineralization in Organic Solvents by Alkylammonium Salts of Ethylenediaminetetra-acetic Acid", Biochem. J., 169, 697-701.
In the paper the authors describe how to obtain an EDTA-ethanol solution by adding triethylamine dropwise. However, I could not reproduce this. I did achieve dissolution but only after adding triethylamine in very large amounts (about 50% of the ethanol volume).
Any ideas why I am not being able to reproduce the obtained results?
Any suggestions on alternative methods to achieve an EDTA solution using an organic solvent (e.g. ethanol)?
Thanks for your *delete me*
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I need to dissolve EDTA in a non-aqueous solution. I tried to follow a protocol described in: Scott et al., 1978, "Demineralization in Organic Solvents by Alkylammonium Salts of Ethylenediaminetetra-acetic Acid", Biochem. J., 169, 697-701.
In the paper the authors describe how to obtain an EDTA-ethanol solution by adding triethylamine dropwise. However, I could not reproduce this. I did achieve dissolution but only after adding triethylamine in very large amounts (about 50% of the ethanol volume).
Any ideas why I am not being able to reproduce the obtained results?
Any suggestions on alternative methods to achieve an EDTA solution using an organic solvent (e.g. ethanol)?
Thanks for your *delete me*
Triethylamine may not be a strong enough base. What are the molar ratios you used?
Try tetra-n-butylammoium hydroxide.
Or how much EtOH did you use, you could try more or do you need a certain concentration?
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Thanks for the feedback!
I followed Scott et al 1978 ( http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1183843/pdf/biochemj00493-0252.pdf ). 58.5mg of EDTA and 780ml of EtOH. The goal was to achieve a final concentration of 0.2M (water would be added at the end to achieve this concentration). However, the authors mention that the EDTA was fully dissolved prior to adding water.
It will take me some days before I can try tetrabutylammonium hydroxide. I found several options of tetrabutylammonium hydroxide solutions, would you recommend a specific type (concentration/chosen solvent)? I found concentrations going from 0.1 to 1M and using water, methanol, toluene/methanol, and isopropanol/methanol. I would expect that the organic solvents to be the best choice.
How much would you expect that I would have to add of the chosen tetrabutylammonium hydroxide solution?
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Use an organic solution of the base.
You will need 4 equivalents, so you can work out how much of a 1.0M solution you will need.
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Use an organic solution of the base.
You will need 4 equivalents, so you can work out how much of a 1.0M solution you will need.
Thanks! I will try it and then get back to this forum.