User:Anthony Salvagno/Notebook/Research/2010/11/18/Making EDTA

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So I realized today that when I made popping buffer a week ago I didn't make sure the pH was at 8.0 and so now I need to remake it so that my EDTA has a pH of 8. I will do a recipe of how much whatever I need to add to make sure that I can do it again without needing to use the pH meter.

Recipe

So I have EDTA Disodium Salt Dihydrate so I can just put this in water to get EDTA. Then I will need to add either NaOH or HCl to get the pH to 8 depending on the pH of the EDTA sans stuff.

Math: EDTA FW: 372.24 and I want 50mL at a concentration of 100mM total so:

• That means I need 1.8612 g of EDTA powder.

Recipe:

1. Measure 1.8612 g of EDTA powder and put it in a falcon tube
2. Add 25mL of DI water.
3. Measure pH
4. Add NaOH until pH reads 8.0
5. Fill to 50mL with DI water

For me, I needed to add ~.525ml of 10M NaOH to get the pH to be 8.0. The EDTA had a pH of ~4.2.