Have you adjusted the pH with NaOH? EDTA is only dissolved at pH around 8.

i have tried to adjust with NaOH and its still not dissolving, maybe my ph meter is faulty

R u stirring constantly with a a bit of heating..only then it dissolves

if u want to prepare 500 ml of EDTA,then wt the appropriate ammount of salt and keep it in a alluminium foil.

Take 350 ml of distill water in conical flask and addjust it's ph approx 7.8 with NaOH pellets. Then put a magnetic bar in the water and keep it on a stirrer. Add aproximate half of salt in it and wt for 5-10 min, it will disolve completely. Then add

remaining salt bit by bit and when it wil dissolve completeley maintain it's volume. If in between it is getting problem to dissolve the salt, add some ammount of water.

Dear Bhavin,

Your EDTA solution will be completly dissolved when you adjust pH. Your your solution will be completly clear once you are close to pH 8.0

dear start adding NaOH pellets in the EDTA slowly, It start dissolving and when you find that solution is becoming cleat stop adding and keep it on stirrer. if it is not dissolved completely then add very least amount of naoh may be from solution or from pellet. when you will find clear solution in such a way. the pH of it would be exactly 8. make up the volume. you can calibrate your pH meter with it.

TC

The best way to dissolving EDTA is use NaOH pellets.

thanks so much guys, i finally made the EDTA, i really appreciate your contributions.

EDTA ll dissolve only if ur pH is around 8 and more

hi, while dissolving EDTA add some NaoH flakes i will dissolve easily....;

Hi Elizabeth, can you please share how you prepared EDTA successfully.. I have failed actually and I need help.

EDTA is not dissolved in neutral water,it must dissolve in basic water.....

I followed this procedure for preparing  0.5M EDTA ph8(100ml) . Initially I  warmed around 70ml of water and added an ml of 6MNaoh solution to shoot up the ph to 7.6  with the container on  a hot plate .Then I slowly added the measured quantity of EDTA and Simultaneously kept adding small volumes of 6M Naoh solution while measuring  the ph.Finally around ph 8 the EDTA was completely dissolved and the process was way too quick..

the simplest way to dissolve EDTA is after making pH 8 just use autoclave with a simple procedure  

6M NaOH prepared at same time of dissolving EDTA is much better. Dont use the NaOH which was already prepared. Prepare yourself at the time you want to dissolve EDTA

6M NaOH prepared at same time of dissolving EDTA is much better. Dont use the NaOH which was already prepared. Prepare yourself at the time you want to dissolve EDTA

Dear Elizabeth Siago Kusia,

Please attach detailed protocol how you dissolved the EDTA alone?

Best

Hi,

Please use the Cold Spring Harbor Protocols for all your mol bio recipes.

To prepare EDTA at 0.5 M (pH 8.0) see this link:

http://cshprotocols.cshlp.org/content/2006/1/pdb.rec8030.full?sid=7e38ebd1-ed55-4287-8aba-8bda25966e5d

Rgds

How to protect EDTA from chelation?

Be patient, add half of the required  water volume and mix using a vortex in a Falcon tube. At the same time, add small amounts of NaOH (drops) and adjust to pH 8.0. When you reach this pH EDTA will dissolve well. As before recommended, is better to buy for the next time EDTA-Na2 which will dissolve faster.

it was my first attempt at preparing 0.5 M EDTA, 

just simply added NaOH pellets, and EDTA could successfully be dissolved,

its was soluble in pH range 7.5 to 8.0. 

The problem occurs when the surrounding temperature is low or high than normal room tempeerature.I experianced the same problem .Just do one thing.Make the pH of distill water 8 and add little of EDTA stir it unless EDTA is fully dissolved.Then again add little EDTA and dissolve .Check the pH in between.During the last stage it is suggested to use 1N NaOH instead of pellets.This works.Good Luck.

 addition of base will improve the EDTA solubility, if you do not want to use base, you need to use time, leave if for a week and most probably it will be completely dissolved

the EDTA that I made is clear but a little babyblue at pH 8.00. should I let is stay than it may change the colour?  

For 50ml of 0.5M EDTA.Na2 I used 9.1 g , then I added 40ml ddH2O +10ml (5N NaOH) with stering to get abou 8.5 pH ,then the EDTA dissolved very easly

Generally The pH of 0 .5M EDTA  from7.5 to 8.0 is okay. When pH of EDTA reaches to 7.5, EDTA solid starts to dissolve. If your EDTA is not dissolved, you can heat it at 60 degree temp with dry machine or any way. until dissolved. I prepared EDTA 0.5M solution before 10 days same way. I added NaOH pellet to increase pH of EDTA and EDTA's pH was 7.9.

For 100ml of 0.5M EDTA (pH 8) :

Add over half of the required  volume of distilled water (~60 ml) to EDTA (14.612gm) . At the onset add 2gm of NaOH pellets and mix by vortexing in a glass beaker with magnetic bead. Check pH using pH paper since initially EDTA will be undissolved. Keep adding NaOH pellets one by one (i usually need 25 to 27 more additional pellets), and keep checking pH using pH paper. Once pH rises to 7.5 on pH paper, then continue to check using pH meter. The EDTA will dissolve completely like magic when pH reaches 8. Then pour the solution back into a glass measuring cylinder and make up to desired volume. Autoclave to sterilize.

You have to gradually add pellets of NaOH & continue to measure the pH.  Your EDTA will eventually fully dissolve once the pH is around 7.5 - 8.  PATIENCE IS A VIRTUE!!

The EDTA will not dissolve except when the pH is in between 7.5 and 8.  So, Please add the EDTA powder on the distilled water under stirring and immediately start adding the NaOH pellets to increase the pH to be between 7.5 and 8.  After the solution gets completely clear lower the pH with the diluted HCl solution to be 7.4.  This solution is suitable to be applied on dentin surfaces in experiments testing dentin hypersensitivity.  

I have increased pH with NaOH pellets until EDTA has completely dissolved (pH was 12 maybe the NaOH pellets were expired), then i diluted it with HCL solution.

Hi try to use NaOH pellets and when you reach pH=8.00 it will be dissolved

Linda may have the answer to this: so exactly what weight of NaOH pellets is needed to make 500mL of 0.5M EDTA? I have been making this reagent for a looong time, but have always been too lazy to do this very simple task!

(which would save me, and all our readers, a lot of time at the pH meter!)

G

Just adjust the PH 8.0, it will dissolve automatically.

Seubhendu: paraphrasing Boromir, you simply don't just adjust the pH of EDTA to 8.0. The student can spend hours doing so, we've all been there.

the CSHL protocol calls for about 20 grams of solid NaOH for 1L of 0.5M EDTA. This will give you a headstart

http://cshprotocols.cshlp.org/content/2006/1/pdb.rec8030.full?sid=7e38ebd1-ed55-4287-8aba-8bda25966e5d

Yet another protocol calls for 2.2 grams of NaOH per 100 ml. Sound about right.

https://sciencing.com/dissolve-edta-water-8194463.html

Andrey, it does not matter with how much NaOH you need to dissolve EDTA. EDTA only goes into solution once the ph 8.0 and this is only achieved by adding NaOH pellet directly to the solution. EDTA automatically get dissolved at ph 8.0 and there is no magic in it.

You can use following amount of NaOH in EDTA to dissolve

For 0.5 M EDTA (pH 8.0)

Mix 186.1 g of disodium EDTA (Na2EDTA) in 800 mL of dH2O and adjust the pH up to 8.0 with adding ~50 ml of NaOH with continuous stirring. Once dissolved, bring volume to 1 L with dH2O , autoclave and store at RT.

Note: EDTA will not dissolve until the pH of the solution is adjusted to 8.0 by the addition of NaOH.

In case if pH is increased than 8, can we add HCL to adjust it ?

that will depend if adding HCL/CL wont affect what you want to achieve