I have experience making EDTA solution before. And I got success when I adjust pH to 8.0 (normally many references suggest this way). But, I can not dissolve it now. What's the problem?
Does anyone know the safe boiling temperature of EDTA in water solution. I want to heat it, but I worry it will be decomposition ( at 200 and 260 °C).
Two preliminary publications describe the reactions of EDTA at elevated temperatures in aqueous solution (1, 2). At moderate temperatures, -- 175°C in alkaline solution, EDTA was found to undergo hydrolytic C-N fission to give iminodiacetic acid (IDA) and hydroxyethyliminodiacetic acid (HEIDA) as the main reaction products (2). The half-life for this first order process at 175°C is 4.5h at pH = 9.4. At 'To whom all correspondence should be addressed. somewhat higher temperatures (2) (200°C) this half-life is reduced to 0.5 h, while a concomitant consecutive reaction involving the further hydrolysis of HEIDA to ethylene glycol and IDA also takes place. At still higher temperatures decarboxylation reactions also occur. Thus at 265"C, the initial hydrolysis products decarboxylate to give Nmethylglycine and dimethylamine. Please have a look at very relevant PDF, quite useful ...
Two preliminary publications describe the reactions of EDTA at elevated temperatures in aqueous solution (1, 2). At moderate temperatures, -- 175°C in alkaline solution, EDTA was found to undergo hydrolytic C-N fission to give iminodiacetic acid (IDA) and hydroxyethyliminodiacetic acid (HEIDA) as the main reaction products (2). The half-life for this first order process at 175°C is 4.5h at pH = 9.4. At 'To whom all correspondence should be addressed. somewhat higher temperatures (2) (200°C) this half-life is reduced to 0.5 h, while a concomitant consecutive reaction involving the further hydrolysis of HEIDA to ethylene glycol and IDA also takes place. At still higher temperatures decarboxylation reactions also occur. Thus at 265"C, the initial hydrolysis products decarboxylate to give Nmethylglycine and dimethylamine. Please have a look at very relevant PDF, quite useful ...
OK. Thank you very much for the explanation and nice suggestion.
Those will help my work.
If you do not have Na-salt of EDTA, then just add ~1 N NaOH drop-by-drop to the EDTA suspension. Better in a stirred beaker under pH control. No need for heating, although it is quite safe: Na-EDTA is stable.
OK Dr. Nicolai S Panikov
Next time, I will try to make it without heating process.
Thanks
hi Muhammad,
its very simple to dissolve EDTA in water just put the water and desired quantity of EDTA in glass bottle and put it on magnetic stirrer for some time it will dissolve it.
if you will add some other salts or chemical it will change the PH of you solution because for DNA extraction you need 8 PH EDTA buffer and it will take more time to maintain PH again
hi Muhammad,
its very simple to dissolve EDTA in water just put the water and desired quantity of EDTA in glass bottle and put it on magnetic stirrer for some time it will dissolve it.
if you will add some other salts or chemical it will change the PH of you solution because for DNA extraction you need 8 PH EDTA buffer and it will take more time to maintain PH again
I have this problem again...
I ajusted the pH to 8.0 with NaOH (~2 gr of NaOH pellets).
Finally I got pH= 8.01, but the disodium salt of EDTA still wouldn't go into solution. Eventhough, I stired it for longtime.
When I added one more pellet, my EDTA will dissolve completely. Then I checked the pH of the EDTA solution, it becomes to 8.2. Is it OK (can I use it)? Thank you.
Should be OK, if not so much. You can try anyway. However, you must report in your paper the pH of the EDTA solution, if succeeded
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