Question

When converting an acid salt dissolved in water to its acid form, you are instructed to adjust the pH well into the acidic range (pH = ~2). Why don’t you just take the pH to neutral? You do the same for adjusting the pH of a solution containing an amine salt taking it well into the basic range rather than neutral. Why are you instructed to do this?

Answer 1

The answer lays in logD.

Step-by-step explanation:

So when you end up with neutral pH amine or either carboxylic acid can still be in a salt form. So for every compound the pH level of unionized form is different and for the best extraction experience is better to perform and extraction at as low as possible pH for acids and for amines as high as possible.