thanks for the advice.

in a new dream ..
1200g glycol washed with 10 liters of 10% NaOH (much)
then the pH was basic ..
dried ...
the first drops of yellow ketone were after was becoming darker colors ..
and then measured the pH was acid!

I do not understand ..
the pH was basic and transformed to acid during distillation?

someone please help me?

You should consider to readjust your expectation frame on how QUICK chemical reactions, even simple ones occur.
If you washed with this amount of lye and in the end its still acidic you foremost did not provide enough time (and mixing probably too).
As a solution has after such a procedure not a certain ph when the paper shows it for the first time, but only when showing a stable not changing ph for a prolonged time.
30 seconds is not a prolonged time btw.
Not even when it appears to you as 15 minutes.
Clocks come handy here.


You will understand better when having watched a cloud of HCl fog sitting over a strong methylamine in IPA solution for hours and you went to bed and in the morning there was still some left.....

Most people are also surprised to read about drying agents listed for acetic anhydride.